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THE PRACTICAL 

Gas and Oil Engine 
Handbook 

A Manual of Useful Information on the 
Care, Maintenance and Repair of 
Gas and Oil Engines 

With Special Reference to the Diesel 
Oil Engine 

By 

L. ELLIOTT BROOKES 

Author of “The Automobile Handbook,” 
“Machine Shop Practice,” etc. 


ILLUSTRATED 


CHICAGO 

FREDERICK J. DRAKE & CO. 
Publishers 








fli7 


Copyright 1917, 1913 and 1905 

BY 

FREDERICK J. DRAKE & CO. 



JUL 3Q 1917 


©CU470478 

/ ‘He> f , 






PREFACE 



This work gives full and clear instructions on 
all points relating to the care, maintenance and 
repair of Stationary, Portable, Marine and Auto¬ 
mobile, Gas and Oil Engines, including How to 
Start, How to Stop, How to Adjust, How to Re¬ 
pair, How to Test, and has been written with the 
intention of furnishing practical information 
regarding gas, gasoline and kerosene engines, 
for the use of owners, operators and others who 
may be interested in their construction, opera¬ 
tion and management. 

In treating the various subjects it has been the 
endeavor to avoid all technical matter as far as 
possible, and to present the information given in 
a clear and practical manner. 

The Author. 











































* 





















Gas and Oil Engine Hand-book 


Actual Horsepower. The expression actual 
horsepower is equivalent to brake horsepower 
and is used to designate the power which an 
engine develops at the driving pulley. 

The actual or brake horsepower of an engine 
is obtained by means of a Prony brake or a 
dynamometer which gives the actual work or per¬ 
formance of the engine in foot-pounds for any 
given length of time. 

Adjustment. Adjusting the parts of a gas 
engine is not generally as well understood as it 
might be. It pays to take time and do the work 
properly, then it will not be necessary to tinker 
with one part or another. 

When main bearings are loose, the balance 
wheel will deflect as shown by the dotted lines 
J J, which is a sure indication that bearings on 
the crank shaft are too loose and allow it to 
spring at every explosion. This play around 
the crank shaft is shown at N in Figure 1, p. 10. 
The bearings have come loose, and sometimes 
the result will be a broken shaft. 

A crank bearing can be run very close if it is 
properly set up and all bolts firm, otherwise it 
will run hot quickly. 


7 



8 


GAS AND OIL ENGINE HAND-BOOK 


The working parts of a gas engine are more 
difficult to keep tight than those of a steam 
engine owing to the high pressure carried in the 
cylinder, both in compression and explosion. 

It is very important to watch a newly adjusted 
bearing for a time after starting the machine. 
If the bearing shows signs of heating stop the 
machine promptly; cool down the overheated 
parts and readjust until the job is right. 

In gas engine practice the bearings for the 
ends of the connecting rod are generally secured 
to the rod proper by bolts and lock nuts. In 
adjusting always make the lock nuts secure 
before leaving the job. 

Anti-freezing Solutions. To prevent freezing 
the water in the jacket when the engine is not in 
operation in cold weather, solutions are used, 
notably of glycerine and of calcium chloride. 
The proportions for the former solution are equal 
parts of water and glycerine, by weight, for the 
latter, approximately, one-half gallon of water to 
eight pounds of calcium chloride, or a saturated 
solution at 60 degrees Fahrenheit. This solution 
is then mixed with equal parts of water, gallon 
for gallon. Use the chemically pure salt only, 
avoiding the use of the crude calcium chloride or 
chloride of lime. 

Another easily prepared solution which may 
be relied upon to withstand a temperature as 


GAS AND OIL ENGINE HAND-BOOK 


9 


low as 20 degrees below zero, F., consists of a 
mixture of one-half clear water and one-half de¬ 
natured alcohol, to which should be added 4 to 
6 ounces of glycerine to prevent the alcohol 
from evaporating. 

Backfiring. Its principal cause is a prolonged 
combustion of the previous charge. When the 
charge entering the cylinder does not contain the 
proper amount of fuel it makes a slow burning 
mixture. This mixture may be so slow in com¬ 
bustion that it continues to burn not only during 
the working stroke, but also during the exhaust 
stroke of the piston, and there still remains 
enough flame in the cylinder to fire the fresh 
charge being drawn into the cylinder. 

Any projecting point in the valve chamber or 
deposits of carbon in the cylinder may become 
heated and serve to ignite the incoming charge. 

Regulating the fuel or air supply will remedy 
the backfiring if caused by a weak or a too 
strong mixture. If this does not remedy it, 
deposits of carbon or projecting points should be 
looked for and removed. 

Bearings. Plain-bearings are almost invari¬ 
ably used in the construction of gas and oil 
engines on account of their simplicity, ease of 
renewal and practically inexpensive construction- 
Figure 2 shows a form of crank shaft bearing 
much used by the builders of stationary gas and 
oil engines. 


10 


GAS AND OIL ENGINE HAND-BOOK 


The ball bearing is one of the many devices 
which involve in their successful operation, or 
application, many steps and in the right 
direction. 

We find the best designs of today still assume 
that the balls and races are round. The neces¬ 
sity of the balls and races being perfectly round, 
as near as possible, is much better understood 
than in the earlier days. Steel is no longer 
implicitly assumed as undeformable as it was 
years ago, for it is dealt with on the basis of 
exactly what it is—a hard, elastic and compres¬ 
sible material. The contacts of the balls with 
the two raceways between which they roll must 
be regulated so that there will be no sliding 
around the race, and further, the sliding contact 
due to the squeezing of the ball and raceway 
together must be reduced to a minimum. 





















GAS AND OIL ENGINE HAND-BOOK 11 


For plain-bearings, the shafts of which are 
continuously running at a high rate of speed, the 
working pressure per square inch should not 
exceed. 400 pounds. As the arc of contact or 
actual bearing surface of a journal-bearing is 
assumed as one-third of the circumference of the 
journal itself, the pressure per square inch upon 
a bearing is 
therefore equal 
to the total load 
upon the bear¬ 
ing, divided by 
the product of 
the diameter of 
the journal into 
the length of the 
bearing. 

Let D be the 
diameter of the 
journal or shaft 
at its bearing, and L the length of the bearing, 
if W be the total load or pressure upon the bear¬ 
ing and P the pressure in pounds per square inch 
of bearing surface, then 

P= JL_ 

r D X L 

The crank shaft bearings are usually set at an 
angle of 45 degrees, they should be heavy, of 
ample area, and readily adjustable. Outside 



fig. 2 

Crank-shaft journal box for gas or oil 
engine, with wick-feed oiling device. 




12 GAS AND OIL ENGINE HAND-BOOK 


bearings should be fitted to large engines where 
the crank shaft overhangs. The connecting-rod 
bearings should be made of phosphor bronze, 
and be made adjustable for wear. 

A rule followed by some manufacturers is to 
make the diameter of the crank shaft from one- 
third to one-half that of the cylinder diameter. 

Bearings, Heated. Heated bearings may arise 
from a variety of causes, such as: 

Eearings of insufficient surface for the load or 
strain put on them, engine running at too short 
centers with a tight belt, bad-fitting or sprung 
crank shaft, bearings screwed up too tight, in¬ 
sufficient lubrication, improper or poor oil, dust 
or dirt in the bearings, oil grooves too shallow or 
oil holes stopped, oil cups or lubricators becom¬ 
ing air-tight and preventing the proper flow of oil, 
from the engine being overloaded. 

Calorific or Heat Values of Fuels. Blast¬ 
furnace gas for operating large engines has come 
considerably into use. It is of low calorific 
value, and requires a high degree of compression, 
but as it is a waste product in most steel mills its 
use will be greatly extended in the near future. 

The calorific value of blast-furnace gas aver¬ 
ages about 100 British thermal units per cubic 
foot, and requires about lj times its volume of 
air for complete combustion. 

What is known as producer gas is now largely 
used in gas engines, and for large engines. When 


GAS AND OIL ENGINE HAND-BOOK 13 


made under favorable conditions, undoubtedly a 
considerable economy is ejected, as the cost is 
usually only about one cent per horsepower, while 
coal gas at 60 cents per thousand feet would 
amount to about 2 cents per horsepower. 

Producer gas is usually made from anthracite 
coal or coke, but a process has been introduced 
in which a superior quality of gas is made from 
bituminous coal, at the same time a large 
amount of sulphate of ammonia is obtained from 
the fuel, thus further reducing the cost of the gas. 

The calorific value of water gas averages about 
400 British thermal units per cubic foot. 

The calorific value of good coal gas is about 
650 British thermal units per cubic foot. 

The calorific value of producer gas is about 
150 British thermal units per cubic foot. 

The caloric value of gasoline gas averages 
680 to 710 British thermal units per cubic foot. 

Cams. The proper form of cam should give 
an easy lift to the valve and a longer time for the 
valve to remain fully open. 

To attain this object the lift of the valve and 
consequently the throw of the cam should be 
about one-fifth more than is actually required 
with the ordinary form of cam, that is to say, 
the valve should lift more than the amount 
required for a full opening, or this additional 
amount of clearance should exist between the 
valve stem and the valve lifter. 


14 GAS AND OIL ENGINE HAND-BOOK 

As the duty of a cam is to transfer rotary 
motion of the cam shaft into the necessary recip¬ 
rocating action required for lifting the valves, the 
quick opening and closing of the valves necessary 
in a four-cycle engine is more easily arrived at by 
means of a cam motion than otherwise. The 
valve is closed by a spring, the operation of 
opening the valve being performed by the cam 
only. 

The width of the face of the cam in contact 
with the roller may be ascertained by calculating 
the work to be done due to the pressure in the 
cylinder at the time of the opening of the valve, 
together with the area of the valve. When the 
inlet valve is mechanically operated the cam con¬ 
trolling its movement may be of less width than 
the exhaust valve cam, as atmospheric pressure 
only is present when it is in operation, as com¬ 
pared with the exhaust valve cam, which has to 
open the exhaust valve against a pressure some¬ 
times as high as 90 pounds per square inch, 
necessarily involving considerable strain. 

0am Shaft Gearing. In the four-cycle gas or 
oil engine the valves are only operated during 
alternate revolutions of the crank shaft. This, 
therefore, requires some form of two-to-one gear. 
A form of spiral gear is well adapted for this work. 
The power necessary to operate the valves is, in 
this case, transmitted from the crank shaft by 
the worm or skew gearing through the cam 


GAS AND OIL ENGINE HaND-BOOK 15 


shaft, with separate cams opening the inlet and 
exhaust valves. Where spur gearing is used the 
cam shaft is mounted in bearings parallel to the 
crank shaft, the cams then operate horizontal 
rods which open the valves. 

Gas or oil engines having the valve operating 
mechanism located near the crank shaft usually 



FIG. 3 

Spur and spiral gear types of cam-shaft gearing. 


have the spur form of gearing to transmit the 
motion from the crank shaft to the cam shaft. 
Engines having the valve mechanism adjacent to 
the valve chamber generally have the spiral form 
of gearing for the above purpose. 

Figure S shows both forms of gearing, with 
the spur gear drive the shafts are parallel, while 





16 GAS AND OIL ENGINE HAND-BOOK 


’viih the spiral form the shafts are at right angles 
to each other. 

The left-hand view in the drawing shows the 
spur gear drive and that on the right hand the 
spiral form of gearing. 

Carburetors—Float Feed. All of the car¬ 
buretors used on automobiles, most of those used 
on marine engines, and many that are used on 
stationary engines are of the float feed auto¬ 
matic type. They are spray carburetors or 
vaporizers so far as projecting the mass of gas¬ 
oline directly into the ingoing current of air 
is concerned, and they obey all the laws for car¬ 
buretors of this class laid down in the following 
pages, but they differ from the simple carbu¬ 
retors which were described, in these particulars. 
They maintain a fairly uniform pressure head 
of gasoline by not permitting it to rise above a 
certain height in the reservoir, and they under¬ 
take to regulate the quality of the mixture at 
all speeds of the engine and under a wide range 
of varying conditions by maintaining the same, 
or practically the same degree of vacuum around 
the point of the spray nozzle. The means by 
which these two things are accomplished can 
best be explained in connection with Figure 4, 
which represents the main essentials of a float 
feed carburetor. 

Gasoline is delivered to the float chamber by 
gravity from a tank placed a little above the 


GAS AND OIL ENGINE HAND-BOOK 17 


cylinder of the engine. The float consists of a 
thin copper vessel closed on all sides with all 
joints carefully soldered to prevent any liquid 
from reaching its interior. 



Sometimes instead of using a metal float, a 
cork float is used. If cork is used it must be 
well shellacked to prevent it from becoming satu¬ 
rated with gasoline and losing its buoyancy. 
When so treated, however, it is very serviceable 
and will remain in good condition a long time. 
The metal float is a very good float as long as it 
remains tight. It may be good for years and it 
may develop a leak in a few weeks. A very 
small leak is much more troublesome, being 


























18 


GAS AND OIL ENGINE HAND-BOOK 


harder to find than a large one. In every case 
the function of the float is to operate a valve 
which admits gasoline into the float chamber. 
This may be accomplished in one of several 
ways. In Figure 4 the valve stem passes easily 
through the float. A grooved collar is secured 
near its upper end which affords a means of 

UJ 

2 

o 

<zr 

r 



connection for a couple of weighted levers piv¬ 
oted at P. When the gasoline falls in the float 
chamber the float also falls, allowing the weights 
on the ends of the levers to drop and lift the 
valve V, thus admitting more gasoline. When 
the float rises it pushes up on the weights and 
forces the valve to its seat. 






















GAS AND OIL ENGINE HAND-BOOK 


19 


Two other methods of arranging the float and 
Valve appear in Figures 5 and 6. The arrange¬ 
ment of the float and its valve is so obvious in 
Figure 5 that no detailed explanation seems 
necessary. 

In the case of Figure 6, we have a cork float 
arranged in the form of a horseshoe, surround¬ 
ing the central air tube or mixing chamber. 



One style of automatic carburetor. 

A—Auxiliary air valve. B—Gasoline reservoir. D—Fuel 
valve cap. E—Needle valve. F—Horseshoe shaped float. 
G—Gasoline supply. J—Float valve pivot. K—Throttle 
valve. T—Drain cock. 

















































20 


GAS AND OIL ENGINE HAND-BOOK 


In Figure 4 the grooved collar may be shifted, 
in Figure 5 the float itself can be set at the 
required height by shifting the nuts on the 
threaded valve stem, but in Figure 6 there is 
no way provided to change the position of the 
float. 

When the piston moves from the head end of 
the cylinder, the pressure of the gas behind it 
drops somewhat below atmospheric pressure. 
When it moves far enough so that the difference 
in pressure between the atmosphere and the gas 
inside of the cylinder is greater than the ten¬ 
sion of the inlet valve spring, then the latter 
will open and the charge will begin to enter the 
cylinder. The pressure in the inlet pipe, right 
close to the cylinder, is practically the same as 
in the cylinder, and gradually increases to prac¬ 
tically atmospheric pressure at the entrance. 

If the piston could be made to move to the 
crank end of the cylinder instantly, the reduc¬ 
tion in gas pressure would occur instantly, and 
the amount of reduction in the inlet pipe or 
carburetor would be much greater than it ever 
is in practice. This would cause a very rapid 
rush of air past the gasoline nozzle and this with 
the help of atmospheric pressure on top of the 
gasoline in the reservoir would cause a more 
than usual flow of gasoline for the given quan¬ 
tity of air. In other words, the mixture would 
be very rich. This, of course, is the limiting 
condition in that direction, but it is easy to see 
that as we approach this condition in actual 


GAS AND OIL ENGINE HAND-BOOK 21 


practice, by means of high speed we must find 
some way to bring the mixture back to its 
proper working composition. This is accom¬ 
plished by means of what is called an automatic 
air valve as shown in Figure 4, which is held to 
its seat by^ means of a light spring. This spring 
is given a certain amount of tension and holds 
the valve shut until the pressure above the spray 
nozzle falls to a point where the tension of the 
spring is not sufficient to hold the valve shut. 
When this point is reached, air rushes through 
the auxiliary air port and to a certain extent at 
least corrects the quality of the mixture, first by 
diluting it with fresh air, and second by pre¬ 
venting too great a reduction of pressure in the 
mixing chamber. 

That certain defects exist in this method of 
controlling the quality is freely admitted by 
everyone who is at all acquainted with the work¬ 
ing of carburetors. There is no uniformity in 
the process of mixing the air and the gasoline. 
The mixture is first made over-rich and then it 
is diluted a certain amount. At slow speeds the 
auxiliary valve does not open, consequently, 
from that point up to the point where it does 
work, the mixture is incorrect—not very much 
wrong, of course—but yet not quite right. 
Then at still higher speeds the mixture is made 
so very rich that enough air cannot pass through 
the auxiliary air port. 

The density of the air, its humidity and its 
temperature have an important bearing on the 


22 GAS AND OIL ENGINE HAND-BOOK 

operation of the carburetor and make it difficult 
to construct one that is able to adjust itself to 
all conditions automatically, and produce a uni¬ 
form mixture. 



FIG. 7 

Floai feed type of carburetor, showing float-chamber, mixing- 
tube and spray-feed. 


In many carburetors there is some device to 
provide for raising or lowering the level of the 
liquid in the float chamber by raising or lower¬ 
ing the float. 


































GAS AND OIL ENGINE HAND-BOOK 23 

Figure 7 shows such a device. By depressing 
the small plunger M, on top of the float cham¬ 
ber, which is normally kept out of contact with 
the float by a spring, the carburetor may be 
flushed. 

Carburetor Adjustment. It is advisable 
before commencing a carburetor adjustment to 
grind in all the valves, especially the inlet, and 
to make certain after the grinding that the 
clearance between the valve stems and tappets is 
sufficient. The slightest leak through an inlet 
valve will play havoc with the mixture at slow 
speeds, for every time the cylinder with the 
leaky valve fires, a quantity of exhaust gas will 
leak into the inlet manifold and contaminate the 
mixture it contains. A curious point about this 
fault is that, while the cylinder with the leaky 
valve may fire perfectly, it may cause one of the 
other cylinders to misfire at low speeds. A small 
leak is the more troublesome to locate, for a bad 
leak past an inlet valve will generally show itself 
by firing the mixture in the inlet pipe and car¬ 
buretor. 

This must not be confused with the firing back 
due to too weak a mixture, which is due to the 
mixture burning so slowly that the residue in the 
cylinder when the inlet again opens is still 
alight, and fires the mixture being taken in. 

So important is this point of leaky inlet valves 
when tuning up a carburetor that it is advisable 
to remove the inlet manifold and test each valve 
separately with a smoking taper or a piece of 


24 GAS AND OIL ENGINE HAND-BOOK 

smouldering paper, which will show up the 
slightest leak by the deflection of the smoke 
when the engine is cranked around. 

Carbureter Nozzle. Admittedly, the ideal 
mixture for use in gasoline engines is one in 
which a proper amount of fuel vapor is homo¬ 
geneously mixed with a proper amount of air. 
It is worthy of note in this connection that the 
mixture cannot be homogeneous in the proper 
sense of the term unless the fuel is present in 
the form of vapor. This state in the mixture 
is, of course, very difficult of attainment, but its 
desirability is beyond dispute. 

By far the greater portion of the weakness 
of the common “spraying” type carbureter is 
attributed to the ineffective way in which the 
nozzle presents the fuel to the air. The nozzle 
or orifice through which the fuel has its exit is 
usually spoken of as the “spraying” nozzle, but, 
in so far as the formation of any spray is con¬ 
cerned, this term, as applied to many of the 
individual nozzles in present use, is a misnomer. 
The use of this descriptive term is applied to 
these nozzles with about as much reason as some 
of the attempts at accomplishing aerial travel 
can be called “flying machines.” That is, it 
conveys an idea as to what is desired, rather 
than what is actually accomplished. 

A simple illustration of the effects of an ap¬ 
proach to homogeneity of mixture can be drawn 
from effects which have been noticed by all: 
Thus, if a pint of gasoline contained in a cylin- 


GAS AND OIL ENGINE HAND-BOOK 25 


drical can without cover be ignited, it will re¬ 
quire a given time for its complete combustion. 
If, however, the same quantity of the fuel is 
poured into a shallow pan, such, for instance, 
as those commonly placed under cars while 
standing on the garage floor, very much less 
time will be required for complete combustion. 

The reason for the reduction in time for com¬ 
bustion in the latter case lies in the fact that a 
vastly greater surface of the fuel is in contact 
with the combustion supporting element, the 
oxygen of the air. 

In each of the three cases the same amount 
of fuel was burned and the same amount of heat 
liberated, but the work accomplished in expan¬ 
sion of the gases of combustion is widely differ¬ 
ent, and inversely proportional to the time re¬ 
quired for the combustion. 

The analogy with the above in a carbureter’s 
action, referred to the performance of the fuel 
nozzle, is obvious, since if fuel is discharged in 
a stream it will simply become spread over the 
surfaces and present but a relatively small sur¬ 
face to the air, with consequent slow combustion; 
but if it is discharged as a spray, in the proper 
sense of the term, it will present an enormously 
greater surface, and will more nearly cause the 
approximation of an ideally homogeneous mix¬ 
ture of vapor and air, with consequently acceler¬ 
ated combustion. 

Another point for consideration is the fact 
that if the fuel presents but a relatively small 


26 GAS AND OIL ENGINE HAND-BOOK 

surface to the air, the combustion will not be 
so complete. It is thus seen that the finer the 
fuel division at the nozzle, the greater the gains 
on two scores—power development and fuel 
economy. 

Care of Gas or Oil Engines, Directions for 

the. Keep plenty of fuel in the tank. 

Water sometimes gets into the fuel tank and 
when this reaches the engine it begins to explode 
irregularly. 

Sometimes the water will freeze in the fuel 
pipe and no fuel will come through. In this 
case, the pipes must be thawed out, which may 
be done without disconnecting, if the joints are 
all good and tight. There is no danger in apply¬ 
ing heat to the pipes unless they are leaking. 

Water in the fuel sometimes freezes on the 
inside of the inlet-pipe. 

By removing the inlet-valve and applying a 
torch this can be safely thawed out. 

The water collects from condensation in the 
tanks and otherwise. 

One cause of obstructions in the inlet-pipe is 
the use of rubber or other soft gaskets. 

This should never be done, as they will soon 
become loose and pieces get stuck in the pipe. 
Use nothing but metal gaskets. A ground joint 
does not require any packing. 

Always use plenty of circulating water. 

Never allow the water in the tank to get lower 


GAS AND OIL ENGINE HAND-BOOK 27 


than the upper pipe connection, as the water can¬ 
not circulate unless this pipe is kept covered. 

The lower water pipe and stopcock are liable 
to become clogged up when using dirty water, 
and it is well to see that they are kept clean. 

Should water passages between the cylinder 
head and the main water jacket become clogged 
up they can be cleaned out by removing the 
cylinder head cover and scraping the passage with 
an old file. 

If after an engine runs from fifteen to thirty 
minutes it becomes unusually warm, it is an indi¬ 
cation that the water is not circulating freely. 

If a gas or oil engine is working properly, it 
should run smoothly to the ear, without pound¬ 
ing either in the cylinder or bearings. The 
piston should work clean and be well lubricated, 
without any carbon or gummy deposit. The 
exhaust gases at the exhaust-pipe should be 
invisible or nearly so. The explosions should be 
regular and should be only reduced in pressure 
when the governor is reducing the volume of 
the charge and allowing only part or none of 
the charge to enter the cylinder. 

Cleaning a Gas or Oil Engine. This should 
be regularly and thoroughly performed at stated 
intervals, as should the carbonized oil be allowed 
to accumulate, a great loss of power may result. 
The whole engine should be taken to pieces, and 
the cylinder, piston, valves, governors and 


28 GAS AND OIL ENGINE HAND-BOOK 


levers taken apart and thoroughly cleaned and 
adjusted. 

To remove the hard carbonized oil from the 
working parts copper tools should be used, and 
when the parts are thoroughly cleaned they 
should be rubbed over with kerosene. If nuts 
are set fast they should not be forced, but be 
loosened with kerosene. By using a little 
powdered plumbago and oil on the screw threads 
setting may be prevented. 

Combustion Chamber, Design of. A simple 
and exceedingly practical construction for a com¬ 
bustion and valve-chamber is shown in Figure 8. 

The inlet-valve is atmospheri¬ 
cally or suction operated, as 
shown in the drawing. The 
ignition plug is placed in the 
center of the end of the cyl 
inder, which is cast integral 
or in one piece and is water- 
jacketed throughout. The 
combined combustion and 
valve-chamber is of funnel 
shape and affords a straight 
path for the passage of the 
gases without crooks or bends. 
Combustion Chamber, Dimensions of. If it 
is desired to ascertain the cubic contents or 
dimensions of the combustion chamber of an 
existing engine, they may be found by filling the 



FIG. 8 






GAS AND OIL ENGINE HAND-BOOK 29 


combustion space with water, then obtaining the 
weight of the water in ounces, which multiplied 
by 1.72 will give the capacity of the chamber in 
cubic inches. If an engine is to be designed with 
a given bore and stroke, the first thing to do is 
to decide on the amount of clearance or combus¬ 
tion space at the end of the cylinder for the gases 
to occupy after compression. 

If the combustion space could be made as a 
continuation or extension of the cylinder bore, it 
would be an easy matter to determine the re¬ 
quired clearance, as it would simply be some 
fraction of the total piston stroke. 

But as the general design of a combustion 
chamber deviates widely from a plain section or 
length of a cylinder as above described, some 
other method must be used to calculate the 
required clearance. 

To do this correctly the required contents of 
the combustion chamber in cubic inches must 
first be ascertained, and then apportioned between 
the valve chamber or chambers and the clearance 
proper which lies directly behind the piston 
head. 

To find the cubic contents of a combustion 
chamber when the degree of compression in 
atmospheres is known: Let S be the stroke of 
the piston in inches and A the area of the pis¬ 
ton in square inches. If N be the number of 
atmospheres compression and C the required 


30 GAS AND OIL ENGINE DaND-BOOK 


contents of the combustion in cubic inches, then 


(N - 1) 

Example: Find the cubic contents of the 
combustion chamber for a motor of 8-inch bore 
and 10-inch stroke with 5 atmospheres com¬ 
pression. 

Answer: Ten multiplied by 50.26 equals 
502.6, which divided by 4 gives 125.6 as the num¬ 
ber of cubic inches required. 

Comparison of Gas and Steam Engines. 
The greater thermal efficiency of the gas engine 
as compared with that of the steam engine and 
its adaptability to use the poorer and cheaply 
produced gases made in producer plants, as well 
as the gases given off from blast furnaces, has 
resulted in its development and manufacture in 
units as high as 10,000 horsepower. 

Until recently the gas engine, requiring no out¬ 
side gas-making apparatus, of 100 horsepower 
was probably the largest unit made. Gas en¬ 
gines up to 2500 horsepower are now being made. 

The production of great quantities of petro¬ 
leum in Texas and California chiefly useful for 
fuel purposes only, and which can be procured 
at a low price as compared with illuminating oils, 
has enabled the oil engine in many locations to 
compete in cost of installation and price of fuel 
with the most economical types of steam engines. 



GAS AND OIL ENGINE HAND-BOOK 31 


There can be but little doubt that large mod¬ 
em gas engines, using a good quality of producer 
or blast-furnace gas free from all impurities, 
compare very favorably on the score of economy 
with the steam engine. This arises from the 
cheapness of the fuel in the first place, from the 
superior calorific value of gas over steam, and 
the more efficient utilization of the heat in the 
gas engine. 

Comparison of Horizontal and Vertical En¬ 
gines. Accessibility of the parts in a horizontal 
engine is always considered a great advantage. 
The piston can always be seen and can be taken 
out of the cylinder and cleaned and replaced 
easiiy in this style of engine, while in a vertical 
engine it is necessary to remove the cylinder 
cover and sometimes the cylinder to gain access 
tc the piston, and it is also necessary to have 
sufficient room above the top of the cylinder to 
lift the piston and connecting-rod out. The con¬ 
necting-rod is more accessible for adjustment 
both at'the crank-pin end and at the piston end 
in the horizontal type. This difficulty, however, 
has been overcome by arranging a removable 
plug in the piston head, which when taken out 
allows access to the piston end of the connecting- 
rod. 

Vertical engines for places where space is re¬ 
stricted and where sufficient head room is avail¬ 
able have the greater advantage of occupying less 


32 GAS AND OIL ENGINE HAND-BOOK 


floor space than a horizontal engine. The 
mechanical efficiency of a vertical engine is, how¬ 
ever, somewhat greater, the friction of the piston 
being less than in the horizontal type of engine. 

Sometimes the vertical type of engine can 
only be used, but for ordinary uses the horizontal 
type of engine seems to be most in favor, one 
important point being the difficulty of suitably 
arranging the carbureting or vaporizing devices 
in the vertical type of engine, which are usually 
placed close to the cylinder, and are not so fully 
under the control of the attendant as in the hori¬ 
zontal engine. 

Comparison of Two and Four-cycle Gas 
Engines. The trend in design of large-size gas 
engines using producer or blast-furnace gas is to 
the two-cycle principle of operation. Where the 
four-cycle principle is adhered to, two or more 
cylinders are necessary. As the four-cycle single¬ 
cylinder engine obtains an impulse only once 
in two revolutions, consequently during three 
idle strokes of the piston the power and speed of 
the engine must be maintained by the momentum 
of the flywheels, necessarily enormous in an 
engine of 500 horsepower or over, for the power 
obtained, in comparison with the flywheel of a 
steam engine of the same capacity. With the 
two-cycle engine of large horsepower, in which 
an impulse is obtained each revolution of the 
crank shaft, nearly double the power is said to 


GAS AND OIL ENGINE HAND-BOOK 33 


be developed as compared with the four-cycle 
engine of the same size. The mechanical 
efficiency is increased, owing to the reduced 
weight of the flywheels, and the weight and cost 
of the engine per horsepower is reduced. 

The difficulty of procuring proper combustion 
in the two-cycle oil engine, where crude oil is 
used, has, however, not yet been entirely over¬ 
come. 

It may be stated that the larger size two-cycle 
engines, to compete with the four-cycle gas 
engine in cost of fuel, can do so only when a 
cheap grade of fuel is used. To use such fuel, 
it is imperative that proper combustion should 
take place in the cylinder. 

Compressed Air Starters. On account of the 
difficulty of starting large engines by hand, self¬ 
starters are used for engines over 10 to 12 horse¬ 
power, and a great variety of methods are in use. 
Compressed-air starters are simple and consist 
usually of a hand or power air pump, which 
forces air under pressure into a tank. 

The air tank is connected with the cylinder, 
and the flywheel being turned till the engine is 
in a position to start, that is when the crank is 
just above the dead center, the compressed-air 
valve is then opened and kept open until the 
piston approaches the end of its stroke. This 
operation is repeated once or twice, if necessary, 
to set the engine in motion. 


34 GAS AND OIL ENGINE HAND-BOOK 


A number of devices are also in use, in which 
charges of gas and air are forced into the engine 
cylinder, and ignited by a separate and special 
device, the operation being repeated till the or¬ 
dinary ignition mechanism comes into play. 



FIG. 9 

Compressed air starter, showing air storage tank and drive from 
line shaft to air compressor. 


Exhaust gases stored by the engine itself, under 
pressure in a reservoir, are also used. 

Figure 9 shows a gas or oil engine equipped 
with a compressed air starter. The air compres¬ 
sor is belt-driven from the line shaft. The stor¬ 
age tank, supply pipe to the engine and starting 
valve are plainly shown- 
































GAS AND OIL ENGINE HAND-BOOK 


35 


Compression. Compression in the gas en¬ 
gine is one of the vital necessities in its succes- 
ful performance. An engine may continue to 
run on a light load under a very low compression 
without any noticeable effect so far as loss of 
power is concerned, but the moment a heavier 
load is put onto it there is trouble on hand, and 
the engine slows down, if it does not give up 
entirely. 

If, however, there is only a light load, the 
poor compression may not be suspected unless 
through trouble in starting, and possibly on ac¬ 
count of increased fuel consumption, when the 
work performed is considered. This is one of 
the results of low compression; that is, fuel 
consumption is out of all proportion to the 
work handled by the engine. 

Low compression, or practically no compres¬ 
sion at all, is the result of bad cylinder, piston 
and ring construction, or of cracked, pitted, 
dirty or corroded valves, or a sticking of the 
valve stems in their seats, or of some worn or 
injured condition of some part that allows a 
pressure leak from the compression chamber. 

It is quite important to detect a leak and lo¬ 
cate its cause promptly, since considerable dam¬ 
age may result if it is allowed to go on un¬ 
checked for some time. 

A packed joint between the explosive cham¬ 
ber and the water jacket is a fruitful source of 
pressure leaks as well as water leaks into the 
cylinder. 


36 GAS AND OIL ENGINE HAND-BOOK 


Compression, Advantages of. High, but not 
excessive, compression of the explosive charge, 
combined with complete combustion and expan¬ 
sion, are the most important factors in the eco¬ 
nomical working of gas and oil engines. 

With a high degree of compression the charge 
of gas and air becomes more homogeneous, is 
more rapidly ignited and with greater certainty, 
consequently the combustion is more complete, 
and the force arising from the explosion of the 
charge greater. 

A smaller cylinder is required to give out the 
same power, and a weaker charge can be ignited. 
If, however, the compression be too great, pre¬ 
mature ignition will occur. 

If the engine loses its compression, it generally 
arises from a defective condition of the exhaust 
or inlet-valves, joints, or piston-rings. The 
valves should be taken out and carefully exam¬ 
ined, and if the valves do not fit properly in 
their seats, they should be carefully ground in 
with fine emery powder and oil, the emery being 
afterwards cleaned off with kerosene. 

If the valve stems are too tight, they should be 
eased with a smooth file. 

It is also very important that the degree of 
compression be adjusted to suit the explosive 
qualities of the fuel used. 

Compression, How to Calculate. The com¬ 
pression in atmospheres of an engine may be 


GAS AND OIL ENGINE HAND-BOOK 37 

readily found by dividing the cubic contents of 
the piston displacement by the cubic contents of 
the combustion chamber in cubic inches, and 
then adding one to the result. 

To ascertain the compression in atmospheres 
of an engine, when the cubic contents of the 
combustion chamber are known: Let S be the 
stroke of the piston in inches and A the area of 
the piston in square inches. If C be the con¬ 
tents of the combustion chamber in cubic inches 
and N the required compression in atmospheres, 
then 



Example: Find the compression in atmos¬ 
pheres of an engine of 4-inch bore and 6-inch 
stroke, whose combustion chamber has a capacity 
of 18 cubic inches. 

Answer: Six multiplied by 12.56 equals 75.36, 
which divided by 18 gives 4.19, and 4.19 plus 1 
equals 5.19, or the compression in atmospheres 
required. 

If it is desired to ascertain the compression in 
atmospheres of an engine, the combustion cham¬ 
ber of which is of such shape that its dimensions 
cannot be accurately calculated, its cubic contents 
may be found by filling the combustion chamber 
with water, and after removing the water, ascer¬ 
taining its weight in ounces, and then multiplying 
the result by 1.72. This gives the capacity of the 



38 GAS AND OIL ENGINE HAND-BOOK 


combustion chamber in cubic inches. The com¬ 
pression of the engine can then be readily calcu¬ 
lated from the formula given herewith. 

Compression, How to Test for Leaks in. 
To discover if there are any leaks in the com¬ 
pression of a gasoline motor, a small pressure 
gauge reading up to at least 75 pounds should be 
screwed into the ignition tube opening or in any 
other suitable opening in the combustion chamber. 
When turning the motor flywheel slowly the 
gauge should indicate at least 70 pounds per 
square inch if the compression is in good condi¬ 
tion. 

To test for leaks, fill a small oil can with 
soapy water and squirt round every joint where 
there may be a possible chance for leakage. 
Get an assistant to turn the flywheel and watch 
for bubbles at the joints. 

If the joints are all tight, next examine the 
condition of the inlet and exhaust-valves, and if 
either of them needs regrinding it should be done 
with fine emery powder and oil. 

When the valves have been ground to a perfect 
fit, if the compression still leaks, the piston-rings 
should be examined, as the trouble will be found 
to be there. 

If there is a leakage by the piston, a hissing 
sound will be heard. This trouble may arise 
from badly fitted or badly worn piston-rings, the 
cylinder scored from insufficient or improper 


GAS AND OIL ENGINE HAND-BOOK 3& 


lubrication, or the cylinder worn oval or out of 
round, or overheated from insufficient cooling. 

If the cylinder is worn, there is no remedy for 
it but reboring. 

Compression, Loss of. If an engine leaks 
compression it will not pull its full load, and 
does not start easily. By forcing the piston back 
against its compression it may be readily deter¬ 
mined whether it leaks or not. Examine both 
the inlet and exhaust-valves and see that they 
are fitting properly. Force them up and down a 
few times by hand to make sure they work freely. 

With the engine at rest, take hold of the fly¬ 
wheel and turn it backwards until the piston 
moves in on the compression stroke with consid¬ 
erable force and if there is no leak the engine 
should move forward one-half or a full revolu¬ 
tion, depending on the force with which it was 
driven in. 

If the valves or ignition tube should leak there 
would be no rebound. 

To find a leak in the packing, remove the 
piston from the cylinder and put a light inside. 

Turn on the water and by looking in, the leak 
may be located. 

Before replacing a gasket, scrape both surfaces 
clean. Use asbestos millboard soaked in oil. 

Put the gasket in place and draw it up tight. 

After the engine has become warm draw up 
che gasket several times until the joint is tight 


40 GAS AND OIL ENGINE HAND-BOOK 

Cooling Systems. What is termed the cool¬ 
ing process, or cooling system, is one of the 
essentials and one which has been the subject 
of as much study and progressive development 
as any other connected with the operation of 
the engine. 

Inventive genius has not yet disclosed the 
secrets of any process by which all the heat 
energy generated in a gas engine cylinder can 
be utilized as motive power. An important 
percentage of it must be permitted to escape, 
and to accomplish the best results its escape 
must be hastened by absorption and radiation 
acting on the outer surface of the cylinder in 
which the combustion occurs. 

It is only a few years since it was thought 
necessary to circulate water around the cylinder 
in sufficient quantity to keep the temperature of 
the overflow down to 150 degrees or lower. This 
required large storage tanks, or the consumption 
of large quantities of flowing water, and in 
winter work was attended with great incon¬ 
venience and often considerable expense. 

Cooling the Cylinder. The process of keep¬ 
ing the heat of the walls and head of the cylin¬ 
der down to the proper temperature is called 
cooling the cylinder. 

It is not intended to make the cylinder cold, 
for a cold cylinder w T ould absorb a great amount 
of the heat of the explosion. As it is the heat 
that does the work the object is therefore 


GAS AND OIL ENGINE HAND-BOOK 41 


to turn the greatest possible per cent of it into 
useful work. 

The usual way of cooling the cylinder is to 
circulate a quantity of water around the cylinder 
and over the head, through a water jacket. This 
water space is generally cast as an integral part 
of the head and cylinder. 

The water must be made to circulate through 
this space or otherwise it would become very hot 
and the temperature of the cylinder walls would 
rise too high. 

This circulation may be obtained by a pump, 
or by the natural heat of the engine. If the 
water for cooling comes directly from a hydrant 
and is allowed to waste after passing through 
the jacket, care must be taken to admit only 
enough to properly cool the engine. 

An excessive supply of cold water pumped 
through the jacket will produce bad results. 

When natural circulation is used a water tank 
is used and placed so that the water level in the 
tank will be higher than the engine cylinder. 
The tank is connected to the water space around 
the cylinder by two pipes, an inlet from the bot¬ 
tom of the tank to the lower part of the jacket 
and an outlet from the top of the cylinder to 
the upper part of the tank. 

As the water in the jacket becomes heated it 
rises through the outlet pipe to the top of the 
water level in the tank. As the heat radiates or 


42 GAS and oil engine hand-book 


leaves the surface the water becomes heavier and 
settles to the bottom of the tank. 

The same water is thus used over and over 
again with only a small loss by evaporation. The 
size of the tank must be in proportion to the size 
of the engine, it must hold enough water so that 
the hot water, coming from the engine,will have 
time to cool before it is needed again in the jacket. 

Oil, instead of water, is being used to a con¬ 
siderable extent by some manufacturers. A 
radiator or system of pipes is used when oil is 
employed and the circulation through the jacket 
is obtained similar to the processes just described 
for water, as the general principles of water 
and oil cooling are the same. As the oil will 
not freeze and burst the jacket a distinct advan¬ 
tage over water cooling is thereby gained. 

The next and last means of cooling the cylin¬ 
der is air cooling. 

The cylinder is made with radiating ribs or 
fins, usually cast on, from which the high heat, 
that passes through the cylinder walls, is radi¬ 
ated to the surrounding air. 

This form of cooling was first exploited in 
small bicycle engines with cylinders ranging from 
2b to Sj inches bore and stroke. Recently it is 
being used by automobile manufacturers to cool 
multiple-cylinder engines. 


GAS AND OIL ENGINE HAND-BOOK 43 


Figure 10 illustrates three cooling systems. 
Three engines are shown, the one on the right 
being equipped with the familiar tank system, 
which is practical for stationary work in an en¬ 
gine protected from cold weather. The oil cool¬ 
ing system is shown in the center, with its iron 
radiators, which is probably the most con- 



FIG. 10 


Three cooling systems. 


venient and compact method of connecting up 
the engine and cooling system on a single base. 
The open jacket system is shown on the left. 
This system is also compact and self-contained, 
and has been demonstrated to be efficient and 
adapted to all sizes of gas engines. 




44 GAS AND OIL ENGINE HAND-BOOK 


Connecting-rods. Connecting-rods of gas 
and oil engines are of various shapes in cross- 
section, but those principally in use are made of 
steel with rectangular or circular section, with an 
adjustable bronze bearing at the crank-pin end. 

The crank-pin end bolts should be so propor¬ 
tioned as to have an area of at least 25 per cent 
of the mean cross-section of the rod. 

A connecting-rod of rectangular section, when 
made of steel, should have a cross-sectional area 
at least 30 per cent greater than the circular one. 
For a rectangular section the width of the rod 
should be at least one-third its mean depth. 

For small engines a good and cheap form of 
connecting-rod may be made of phosphor bronze 
or cast steel. 

Crank Shafts. The crank shaft of a gas or 
oil engine should be made of sufficient strength 
not only to withstand the sudden pressure due to 
the explosion, but also to withstand the strain 
consequent upon the greater explosive pressure 
which may possibly be caused by previous missed 
explosions. The crank shaft should be propor¬ 
tioned with relation to the area of the cylinder 
and the maximum pressure of the explosion. 

The mechanical efficiency of an engine may be 
gauged by the strength of the crank shaft, because 
if the crank shaft is not sufficiently strong, it will 
spring at each impulse, causing the flywheels to run 
out of true and also wear the bearings unevenly. 


GAS AND OIL ENGINE HAND-BOOK 45 


The balancing of the crank shaft and recipro¬ 
cating parts is an important feature of a gas or 
oil engine. With a single-cylinder explosive 
engine, to perfectly accomplish the balancing is 
impracticable. Most manufacturers, therefore, 
only balance their engines as far as the recipro¬ 
cating parts are concerned. 

Balancing by means of a recess in the rim of 
the flywheel has the advantage of requiring no 
extra metal, and is cheaper as regards workman¬ 
ship as compared with the method of balancing 
the crank shaft by means of counterweights. In 
each of these methods, however, the flywheel 
itself is out of balance, and when rotating tends 
to make the crank shaft run out of true. 

As it is important that the crank shaft be of 
ample strength, it is the best practice to make it 
forged steel cut from the solid and finished 
bright all over. If the crank shaft be too weak, 
it will spring with the force of the explosions, 
thereby causing undue wear on the bearings. 

Cycles of Gas and Oil Engines. The four¬ 
cycle engine, having only one working stroke or 
imoulse during each two revolutions of the crank 
shaft, consequently requires larger and heavier 
flywheels than a two-cycle engine in order to 
maintain a practically uniform speed and also to 
transmit the power during the idle strokes of the 
engine. 

The four-cycle engine has, however, many 


46 GAS AND OIL ENGINE HAND-BOOK 


advantages over the two-cycle engine. The work¬ 
ing stroke or impulse is more readily controlled, 
and during the inlet and exhaust strokes a longer 
time is allowed for the cooling of the valves and 
the more thorough expulsion of the exhaust 
products from the cylinder than is possible with 
a two-cycle engine. 

In the two-cycle type of engine the charge must 
be independently compressed before entering the 
cylinder of the engine, in some two-cycle engines 
this is accomplished in a separate cylinder, but 
usually in the crank case of the engine. 

A greater quantity of lubricating oil and 
more cooling is required with a two-cycle than 
a four-cycle engine on account of the greater 
amount of heat generated in the same length of 
time. 

Six-cycle or scavenging engines have been 
largely used, in which after the termination of 
the exhaust stroke, a charge of air is drawn into 
the cylinder and the products of combustion thus 
entirely expelled. 

As such engines have only one working stroke 
or impulse to every three revolutions of the 
crank shaft, the cylinder and flywheel dimension® 
require to be greatly in excess of those of engines 
of the four-cycle type, necessitating greater floor 
space, increased weight, excessive wear and tear 
and greater complication of the valve-operating 
mechanism. 


GAS AND OIL ENGINE HAND-BOOK 47 


Cylinders, Construction of. Cylinders made 
with a loose head require the joint to be made 
with great care. An asbestos or copper ring is 



FIG. 11 

Gas or gasoline engine cylinder, with detachable water-cooled 
head. 


used to make this joint, sometimes wire gauze 
with asbestos is used, which has been found to 
give very good results. 

Figure 11 shows a cylinder with a loose water- 
jacketed head in which both the inlet and exhaust- 



FIG. 12 

Gas or oil engine cylinder, with cylinder and head cast integral. 

valves are located. This style of cylinder has 
feet or lugs on either side to attach it to the bed¬ 
plate. 
















48 GAS AND OIL ENGINE HAND-BOOK 


A form of cylinder is shown in Figure 12 in 
which the cylinder and head are integral or cast 
in one piece, it has a separate valve-chamber 
(not shown) which bolts on the side of the cylin¬ 
der and communicates with the combustion 
chamber by a port or passage shown in the draw¬ 
ing. This style of cylinder is attached to the bed¬ 
plate by means of a circular sleeve which fits 
into an opening at the end of the bed-plate and 
is drawn up against the circular flange shown by 
means of bolts. 

Cylinder, Method of Boring a. A good way 
to bore a cylinder is to make a boring-bar to fit 
in the drill socket of a back-geared drill press 
and a brass or phosphor bronze bushing to fit in 
the center hole of the table of the drill press. 
The cylinder can be clamped to the table of the 
drill press by its flange and bored out with a 
cutter set in the boring-bar. Not less than three, 
and preferably four cuts, should be taken to 
make a good job. A mandril should then be 
made with two flanged hubs, one of which should 
be fastened to the mandril and the other turned 
slightly taper so as to make a snug fit in the 
cylinder bore when in place. The ends of the 
cylinder can then be finished on the mandril and 
a perfect job will be the result. In case a back- 
geared drill press is not handy the cylinder can 
be clamped to the carriage of the lathe, bored 
out with a bar in the lathe centers and the ends 


GAS AND OIL ENGINE HAND-BOOK 49 


Pnished in the manner above described, but it is 
a much slower job than in a drill press. The 
cutter for the bar should be made from a piece 
of round tool steel not less than five-eighths of an 
inch diameter. It can then be readily adjusted 
to any desired angle to obtain the best cutting 
effect. 

Cylinder Sweating. Sometimes water will 
collect in the cylinder as a result of the interior 
walls of both the cylinder and cylinder-head 
sweating. This, however, does not often happen 
except on very warm days when a considerable 
volume of cold water has been allowed to flow 
through the water-jacket after the engine has 
been shut down, and this seldom applies where the 
thermo-syphon water-cooling system is used. It 
is more liable to happen where the cold water 
from a hydrant has been allowed to flow through 
the water-jacket. 


50 GAS AND OIL ENGINE HAND-BOOK 

De La Vergne Type “FH” Crude Oil 
Engine. This engine operates on the four- 
stroke cycle and uses crude petroleum as fuel. 
It is built in sizes ranging from 150 H. P. to 
1200 H. P. While retaining the Diesel prin¬ 
ciple of self-ignition, it has the advantage of 
lower compression pressures due to the fact that 
at the end of the compression stroke and the 
beginning of the working stroke the atomized 
fuel, instead of being admitted directly into the 
cylinder, is projected into a separate, uncooled 
combustion chamber within which there exists, 
at the end of the compression stroke, an air 
pressure of 280 lbs., or 19 atmospheres. The 
compressed air necessary for fuel injection is sup¬ 
plied at the proper pressure by a two-stage air 
compressor driven by an eccentric on the main 
shaft. 

The air compressed by the first stage is stored 
in the starting tanks, which also act as a re¬ 
ceiver and intercooler between stages. Figure 
12 a shows a view of a twin cylinder type “FH” 
300 H. P. crude oil engine, in which the air 
compressor, governor and valve-operating me¬ 
chanism are all plainly outlined. The main 
piston is 21 inches in diameter by 52 inches in 
length, having a projected area of 1090 square 
inches and a maximum transverse pressure of 12 
lbs. per sq. in. The connecting rod is 106 inches 
in length. Piston rings are of a special cast 
iron, peened and ground so as to maintain a 


GAS AND OIL ENGINE HAND-BOOK 


51 


perfect cylindrical form. The pistons and cyl¬ 
inder liners are of the hardest cast iron, spe¬ 
cially treated to remove internal stress and thus 
avoid warping. The pistons are ground to mi¬ 
crometer dimensions. The wrist pins are case- 
hardened and ground. 



FIG. 12a 

300 H. P. twin cylinder, Type “FH” De La Vergne crude 
oil engine 


The inlet and exhaust valves are vertical, 
which arrangement has proven to be the most 
reliable. These valves are guided by dashpots 
on the end so as to reduce the wear on the stems. 
Both the inlet and exhaust valves are in remov¬ 
able cages, the exhaust valve cages being water- 
cooled. The replacement of pistons and liners 
constitutes the renewal of all the reciprocating 
wearing parts. The cam rollers and lever ful- 
crums are all equipped with bronze pins. All 
gears are arranged to run in an oil bath. The 




52 


GAS AND OIL ENGINE HAND-BOOK 



outboard bearing is arranged for adjustment 
by shims. 

Combustion Chamber. Figure 12b is a trans¬ 
verse section of the engine showing the con¬ 
struction of the combustion chamber, inlet and 


FIG. 12b 

Transverse section of De La Vergne crude oil engine, 
showing combustion chamber, inlet and exhaust 
valves, governor, etc. 

exhaust valves, the governor, and the fuel atom¬ 
izer, or spray valve. The combustion chamber 
appears in the left portion of the illustration 
directly opposite the spray valve. The com¬ 
bustion chamber is located on the side of the cyl¬ 
inder head, and leads directly from the clearance 
space between the two main valves. In starting, 
the combustion chamber is heated by a blast lamp 






GAS AND OIL ENGINE HAND-BOOK 


53 


during a period of from 7 to 15 minutes, but 
this heating is discontinued as soon as the engine 
has attained the proper speed, the combustion of 
the fuel then maintaining the chamber at the 
proper temperature. 

Governor. The governor is of the centrifugal 
type operated by worm gears from the lay shaft. 
The quantity of fuel passing to the spray valve 
is controlled by an overflow valve in the discharge 
line from the oil pump, the degree of opening of 
this valve being regulated by the governor. When 
the engine runs slightly above normal speed, the 
overflow valve is caused to open wide and permit 
more oil to return to the stand pipe, or if the 
speed should slacken the governor closes the 
overflow valve, thus increasing the quantity of 
oil passed to the spray valve. It is claimed by 
the builders that the variations in speed do not 
exceed & per cent with ordinary variations of 
load. Figure 1 2c shows the construction of the 
governor and fuel pump. 

Fuel Control. The fuel is preferably stored in 
an underground tank outside of the building 
from which it is raised to a small filter stand 
pipe, by a rotary pump driven continuously by 
the engine. The action of the pump keeps the 
stand pipe full and the surplus overflows and 
returns to the tank. From the stand pipe the 
oil is withdrawn by the feed pump on the engine 
and delivered to the spray valve. Here it comes 
in contact with the injection air and when the 
valve is opened the fuel is forced through a 


54 


GAS AND OIL ENGINE HAND-BOOK 



series of channels where it is thoroughly emulsi¬ 
fied before passing through to the combustion 


FIG. 12c 

Governor and fuel pump 

chamber. It should be noted that the oil passes 
through three stages before ignition: 

1. Emulsified wuth air in spray valve. 

2. Atomized upon leaving spray valve. (On 














GAS AND OIL ENGINE HAND-BOOK 


55 


account of the lower cylinder pressure each tiny 
bubble in the oil emulsion bursts as it enters.) 

3. Heavy particles impinge on hot surface 
and gasify. 

Starting and Stopping. The engine is started 
automatically by the admission of compressed 
air to the cylinders, this air being supplied from 



FIG. 12d 

Side elevation in section 


the air tanks previously referred to. For start¬ 
ing, it is only necessary to heat the combustion 
chamber, place the crank in starting position and 
open the air cock. A cam on the lay shaft then 
successively opens and closes the starting valve 
at the proper times. 

When combustion has commenced and the en¬ 
gine begins to gather speed, the air cock should 
be closed. To stop the engine, it is only neces¬ 
sary to cut off the supply of fuel. A side sec¬ 
tional elevation is shown in Figure 1 2d. 



56 GAS AND OIL ENGINE HAND-BOOK 

Operation. To complete the cycle of opera¬ 
tion, four strokes of the piston or two revolu¬ 
tions of the crank shaft are required. 

( a ) Suction Stroke. —The first outward stroke 
is the suction stroke during which the air valve 
(above the combustion chamber), is opened by 
the valve rod and permits the charge of air to 
be drawn into the cylinder. 

(b) Compression Stroke.— The suction stroke 
is followed by the compression stroke, during 
which the air valve is closed, and the charge of 
air only is compressed into the combustion space. 
At or near the end of the compression stroke, 
when all the air is compressed into the combus¬ 
tion chamber, the crude oil fuel, now churned to 
an emulsion by the injection air, plunges as oil 
mist through the confined charge of heated air, 
and an instant later the heavier particles, strik¬ 
ing the hot walls of the combustion chamber, 
gasify and ignite the entire charge. 

(c) Working Stroke. —A perfect mixture 
has been made by the light particles and ignited 
by the heavier particles as they impinged on the 
hot surface of the vaporizer. The combustion 
takes place at once and the resulting gas ex¬ 
pands into the cylinder, forcing the piston for¬ 
ward on its wmrking stroke. 

(d) Exhaust , or Scavenging Stroke. —Near 
the end of the working stroke, the exhaust valve 
(below the combustion chamber) is opened, the 
gas escapes and the piston, on its return stroke, 
expels completely the burnt charge. 


GAS AND OIL ENGINE HAND-BOOK 


57 


Fuel Consumption .—For the type “FH” en¬ 
gine fuel consumption does not exceed the fol¬ 
lowing quantities of any crude oil, distillate or 
fuel oil produced in the United States or Mexico, 
the power to be measured on the engine shaft 
and the fuel to have a lower heat value of not 
less than 18,000 B.T.U. per pound containing 
not over 1% of water. These guarantees are 
made irrespective of the gravity of the fuel or of 
its sulphur content. 

Full load—0.5 lbs. per brake horsepower hour. 

Three-quarter load—0.5 lbs. per brake horse¬ 
power hour. 

One-half load—0.57 lbs. per brake horsepower 
hour. 

“Gas House Tar,” which is the residual by¬ 
product in the manufacture of illuminating gas, 
can also be used satisf actorily- in the De La 
Vergne engine. Some of these engines are being 
operated continuously on this fuel, and when op¬ 
erated at from three-fourths load to full load 
they have a fuel consumption of not over 0.65 lbs. 
per B.H.P., provided the tar has a lower heat¬ 
ing value of not less than 17,000 B.T.U. per 
pound, and does not contain over two per cent 
of water. An oil consumption of less than 0.4 
lbs. per B.H.P. per hour has been more than 
once recorded. One of the tests on record shows 
a consumption as low as 0.374 pounds of oil per 
B.H.P. per hour. 

Twin Cylinder Type “D.HOil Engine. This 
engine, a view of which is shown in Figure l%e, 


58 


GAS AND OIL ENGINE HAND-BOOK 


is the latest type of the De La Vergne oil engine. 
It is designed especially for the use of low grade 
fuels, and is equipped with a separate uncooled 
vaporizer chamber, shown in section in Figure 
1 %f. The action of this vaporizer is as follows: 
The atomized fuel is injected against the hot 


FIG. 12e 

Twin cylinder type “DH” oil engine 



vaporizer walls, producing instantaneous and 
complete combustion, and as the oil is kept out 
of the cylinder, only the expanding gases come 
in contact with the piston and cylinder w T alls. 
This is an advantage when compared with the 
injection of coarse and impure fuels directly 
into the cylinder. The vaporizer has a large 
heated area, thus making the use of high pres¬ 
sures in the combustion chamber unnecessary. 
The pressure need not exceed 150 lbs. per sq. in. 



GAS AND OIL ENGINE HAND-BOOK 


59 


Lubrication .—Two systems of lubrication are 
used on the De La Vergne engine, the individual 
system, and the continuous gravity system. With 
either system the cylinder lubrication is by force 



FIG. 12f 

Cross section through vaporizer 


feed. Since the cylinder, air compressor and 
valve stems must be lubricated with a special oil, 
these are kept separate from the bearing lubri¬ 
cation. 

With the individual system the main bearings 
















60 GAS AND OIL ENGINE HAND-BOOK 

are lubricated with ring oilers by which the oil 
is carried from the cellars to the top of the shaft 
and passing through the bearings, returns to the 
cellars. The crank pins are lubricated by a cen¬ 
trifugal ring oiler, fed from a cup, and the wrist 
pin and eccentric likewise obtain their lubricant 
from cups with sight feeds. With this system a 
De La Vergne settling tank may be profitably 
employed. The oil caught in the frame is depos¬ 
ited in it from day to day until filled, when clean 
oil may be drawn from the proper compartment. 

Cooling Water .—The cooling water required 
for this engine is at full load approximately only 
three gallons per brake horsepower per hour. 
This water may be discharged at a temperature 
of 180° Fahr. 

In locations where water is costly or difficult 
to obtain, this feature is of great value, as a 
water-cooling device of the simplest and most 
inexpensive character allows the circulating water 
to be used again and again with the addition of 
only about five percent of “make-up” water. 

Deep Well Pumping Plants. A deep well 

pumping plant operated by a gasoline engine 
through a single reduction gearing is illustrated 
in Figure 13, the pump is of the single-acting 
type and is connected to the reduction gear by 
means of a pitman-rod with a forked lower end. 
Such plants are also used for draining mines 
and quarries. 


GAS AND OIL ENGINE HAND-BOOK 


61 



FIG. 13 

Deep well pumping plant, showing engine, reduction gear, 
pitman-rod and pump. 























































































































62 


GAS AND OIL ENGINE HAND-BOOK 


Design of Gas and Oil Engines. Gas and 

oil engines should be of substantial design in 
order to withstand the continual shock and vibra¬ 
tions to which they are subject, and should be as 
accessible as possible in the working parts, which 
may require adjustment while in actual service. 
The starting gear and other parts to be handled 
by the attendant when starting and running the 
engines should be placed in close proximity to 
each other. 

Simplicity in construction is the essentlial fea¬ 
ture of a gas or oil engine. The oil engine is a 
machine intended for use in any part of the 
world where its fuel is obtainable, and where, 
perhaps, no mechanic is available. Accordingly, 
all the mechanism should be arranged so as to 
be easily removed for examination and repair. 
The igniting device, as well as the carbureter or 
vaporizer, should be so designed as to facilitate 
removal and repair. A gas or oil engine, to be 
successful mechanically and commercially, should 
be so designed that it can be successfully oper¬ 
ated, cleaned and adjusted by unskilled attend¬ 
ants. 


GAS AND OIL ENGINE HAND-BOOK 


63 


Diesel Oil Engine. This is an internal com¬ 
bustion engine which takes its fuel, crude low 
grade fuel oil or the residues from oil refining, 
directly into the cylinder and there converts it 
into energy. This engine is now built in both 
the four-stroke cycle, and the two-stroke cycle 
styles. Vaporization of the oil takes place within 
the cylinder itself, where the pressure of com¬ 
pression is carried sufficiently high to cause com¬ 
bustion of the fuel. The oil is injected through 
a valve at the top of the cylinder, which is ver¬ 
tical, and as the fuel enters the cylinder after 
the period of compression, about 600 pounds 
pressure per square inch is required for the in¬ 
jection. This pressure is supplied by an inde¬ 
pendent air compressor. The air necessary to 
support combustion is introduced through an 
air inlet valve. 

Figure 13 a represents cross-sections of the 
working cylinder and head of a stationary two- 
stroke motor. The arrangement of slots in the 
cylinder wall, through which the exhaust gases 
leave the working cylinder, as the piston comes 
near the lower dead point, is, of course, a typical 
feature of two-stroke motors. This arrange¬ 
ment is an undoubted advantage over four-stroke 
motors, which discharge their exhaust gases 
through valves. The admission of scavenging 
and charging air is affected through four valves, 
arranged symmetrically in the cylinder head. 

As seen from Figure 13 a, the piston comprises 
at its upper end a cooling compartment, pistons 


64 


GAS AND OIL ENGINE HAND-BOOK 


above a given size having to be cooled with 
water or oil. Telescoping tubes through which 
a water jet in free contact with air is projected 
directly against the bottom of the piston serve 



FIG. 13a 

Sectional view of Diesel two-stroke cycle engine 


to admit and carry away cooling water, an ar¬ 
rangement which avoids any stuffing boxes. 

It is true that the two-stroke process entails 
the use of a special scavenging pump to dis¬ 
charge the exhaust gases. Four-stroke motors, 
which are more simple from a constructive point 
of view, are therefore generally preferable for 















GAS AND OIL ENGINE HAND-BOOK 


65 


small and medium installations. In connection 
with large units, the addition of an air pump, 
however, is of much less importance, the more 
so as the pump discharging the scavenging air 
works at very low pressures and accordingly 
under extremely favorable conditions. On the 
other hand, the reduction in weight is of para¬ 
mount importance for large units, the frames, 
bases and flywheels of large four-stroke motors 
being so heavy that their transportation and 
erection entail serious difficulties. 

The two-stroke Diesel motor resembles the 
four-stroke type as far as its outside arrange¬ 
ment is concerned. The cylinders are likewise 
vertical; their j ackets are cast of one piece with 
the frame, the working cylinders are encased and 
the piston is designed as crosshead. Apart from 
the air compressor, which serves to introduce 
fuel oil into the cylinder and to start the engine, 
two-stroke motors comprise a scavenging air 
pump arranged, in accordance with local con¬ 
ditions, in the basement or above the floor. The 
scavenging air valves, like the other valves, are 
arranged in the cylinder head. The exhaust 
valves are, however, replaced by slots in the 
working cylinder and the fuel supply is regulated 
automatically in accordance with the load on the 
engine. All motors of this type have an attach¬ 
ment for changing speed during operation. 

Figure 13 b shows a cross-section through a 
directly reversible Sulzer-Diesel marine engine, 
which has likewise been designed as two-stroke. 


66 


GAS AND OIL ENGINE HAND-BOOK 


In connection with large units the special regu¬ 
lation developed by the constructors would seem 



FIG. 13b 

Section of Diesel two-stroke marine engine 


to deserve more than passing notice. These en¬ 
gines are thus in a position to deal with any 
sudden fluctuations in load with least variation 
in speed and at the same time can be readily 


















































GAS AND OIL ENGINE HAND-BOOK 


67 


connected up in parallel with any other prime 
movers of the same or any different type, such 



FIG. 13c 

Scheme of injection air regulation 
Diesel engine 


as steam engines, gas motors and water tur¬ 
bines. The working of the regulator will be 
understood by referring to Figure 13c. 

The governor controls, in accordance with its 



































68 


GAS AND OIL ENGINE HAND-BOOK 


adjustment, all the factors on which the output 
of the engine depends. These factors in the 
case of Diesel motors are the amount of fuel 
injected, the amount and pressure of the injec¬ 
tion air required for vaporizing and injecting 
the fuel, as well as the variable admission of the 
vaporizer valve in accordance with the amounts 
of air and fuel. The amount of fuel, as well 
as the amount of pressure of the injection air 
are adjusted for directly from the regulator. 
The regulation of the amount of injection air 
in the present instance is effected by adjusting 
a slide fitted into the suction conduit of the first 
stage of the injection air pump. The adjust¬ 
ment of the duration of opening of the fuel 
valve, on account of the valve resistance, how¬ 
ever, requires much more energy, so that the 
action of the regulator itself would not be suf¬ 
ficient. A pilot valve S has therefore been pro¬ 
vided, which is operated by the pressure from 
one of the stages of the injection air pump. 
In the present instance the pressure obtaining 
between the first stage 1, and the second stage 
k, of the injection pump ds used for this pur- 
the conduit u serving to transmit this pressure 
to the pilot valve S. 

Ignition and Combustion .—The action taking 
place within the cylinder of a Diesel engine may 
be briefly explained as follows: The oil fuel is 
injected through the fuel valve located in the 
top of the cylinder which is vertical. This valve 
is opened by a cam just before the piston has 


GAS AND OIL ENGINE HAND-BOOK 


69 


reached its top center and the injection of the 
fuel oil then commences and continues until the 
piston, after passing the top dead center, has 
moved through about 10 per cent of its down¬ 
ward stroke. 

Owing to the high pressure now prevailing 
in the combustion chamber, which is that portion 
of the cylinder space above the piston, a tem¬ 
perature is produced which exceeds the ignition 
point of the fuel oil and as a result, the oil 
having entered the cylinder in an extremely pul¬ 
verized state, is at once ignited and is combusted 
under approximately constant pressure. 

This pressure is maintained in two ways, first, 
by the compression pressure exerted by the pis¬ 
ton on its up-stroke; second, by the admission 
of compressed air under a pressure exceeding 
that of compression; this air being required for 
the injection of the charge of fuel oil. 

The pressures usually required for the injec¬ 
tion of the fuel oil into the combustion chamber 
of a Diesel engine range from 450 to 600 lbs. 
per sq. in., depending upon the style or make 
of the engine, and also upon local conditions. 
This supply of compressed air is obtained from 
one or more high pressure air compressors, usu¬ 
ally driven from the main cross-head of the en¬ 
gine by means of links and beams. The air 
compressor is of the tandem compound type, 
two or three stage, the low pressure stage being 
double acting, while the intermediate and high 
pressure stages are single acting. 


70 GAS AND OIL ENGINE HAND-BOOK 

Cooling coils are provided for each stage. 
The piston and discharge valves of the low press¬ 
ure stage are of the flat disk type, while those 
of the higher stages are of the poppet type. 
The high pressure air is delivered to a pipe, 
common to all the cylinders of the engine. This 
pipe conveys the air through separators to the 
spray-air bottle from whence it leads to the fuel 
inlet valve bodies in the cylinder heads. The 
number of cylinders in the ordinary Diesel engine 
is four. In some cases there are six. 

Starting a Diesel Engine. In starting an 
engine of the two-cycle type, compressed air 
at a pressure of about 650 lbs. per sq. in is 
admitted to those cylinders whose cranks are 
in the proper position for running in the desired 
direction. 

After the engine begins to turn, starting air 
from a receiver in connection with the spray 
air bottle is admitted to each cylinder from 10 
degrees past the top center, to 85 degrees past 
the top center until the engine has attained suffi¬ 
cient speed for fuel admission. 

Just before fuel admission occurs clean air 
from the scavenging receiver has been com¬ 
pressed in the working cylinders to about 450 
lbs. pressure per sq. in., and when the engine 
is running normal, fuel admission to each cylinder 
occurs as follows: When the piston on the up¬ 
stroke is within 2^/2 degrees of the top center 
the fuel admission valve opens and remains open 
until the piston has reached a point 37 degrees 


GAS AND OIL ENGINE HAND-BOOK 


71 


past the top center, when the valve closes and 
combustion occurs. The exhaust ports in the 
two-cycle engine are uncovered 35 degrees be¬ 
fore the piston has reached bottom center. At 
a point degrees before the exhaust ports 
start to be uncovered, two scavenger valves in 
the cylinder head are opened by the camshaft 
admitting fresh air at 7 or 8 lbs. pressure to 
the cylinder for scavenging. 

The exhaust ports are again covered by the 
piston at 35 degrees past bottom center and 
compression begins. 

The scavenger valves remain open until 31 
degrees after the exhaust ports are closed by 
the piston on its up-stroke. From this point 
compression takes place until degrees be¬ 

fore top center is reached, when the fuel valve 
again opens. 

Speed .—The speed is regulated by the con¬ 
trol of certain factors in connection with its 
operation, as, for instance, the amount of fuel 
injected, the amount and pressure of the com¬ 
pressed air required for vaporizing and inject¬ 
ing the fuel; also the variable admission of fuel 
by the vaporizer valve in accordance with the 
amounts of air and fuel. The two latter fac¬ 
tors are adjusted directly from the regulator. 
The air pressure supply is controlled by ad¬ 
justing a slide fitted into the suctions of the 
low stage cylinders of the air compressor. The 
quantity and pressure of the spray or injection 
air is thus easily regulated. The duration of 


72 GAS AND OIL ENGINE HAND-BOOK 



FIG. 13d 

Section through scavenger compressor 
Two-cycle Diesel oil engine 


























































































































GAS AND OIL ENGINE HAND-BOOK 


73 


opening of the fuel valve is adjusted by the 
action of the regulator in conjunction with the 
pilot valve which is operated by the pressure 
from one of the stages of the air compressor. 
A centrifugal type of governor is used to effect 
this regulation. 

Diesel Marine Type .—Figures 13d and 13tf 
show sections through the principal working 
parts of a large marine engine of the Diesel 
type. The engine will develop about 2500 H. P. 
at 130 R.P.M. and is of the two-stroke cycle, 
six-cylinder crosshead design. Referring to 
Figure 13d it will be seen that the scavenging 
pumps are mounted on the outboard columns of 
the even-numbered cylinders and are driven by 
links and beams from the main crossheads. Each 
scavenging compressor is double-acting and 
draws the air from both sides of the piston 
through the outboard side of the scavenging 
cylinder and then through 12 flat-disk suction 
valves, six for the top and six for the bottom 
of the compressor. The air, after compression 
to about 8 lbs., passes through 12 discharge 
valves and two coolers to the receiver. The 
suction and the discharge valves are assembled 
in six units, each consisting of two suction and 
two discharge valves mounted on one stem. By 
removing the valve bonnets the valve units are 
readily accessible and easily removed. 

Directly under each scavenging compressor 
and driven by the same crosshead are two pumps. 
These supply fresh water for cooling the pistons, 


74 GAS AND OIL ENGINE HAND-BOOK 


^^jjScavenging 



FIG. 13e 

Section through cylinder and air compressor 
Two-cycle Diesel oil engine 






























































GAS AND OIL ENGINE HAND-BOOK 


75 


lubrication for the main crankpin crosshead and 
thrust-block bearings, salt water for cooling all 
the engine parts except the pistons and service 
for bilge and sanitary systems. 

The high pressure air compressors are mount¬ 
ed on the outboard columns of the odd-numbered 
cylinders and are driven from the main cross-head 
by links and beams, as will be seen by reference 
to Figure 13e. 

A small fuel-oil supply pump is attached to 
the No. 1 outboard column and is driven by the 
beam. This maintains the fuel supply from the 
ship’s bunkers to the engine-room tank. The 
fuel-oil-measuring or cylinder supply pumps are 
six in number, one for each cylinder. Two are 
contained in one body, and all the pumps are 
driven by eccentrics from the main camshaft. 
Each fuel pump has a mechanically operated suc¬ 
tion valve and two discharge valves in series. 
The speed and power of the engine are con¬ 
trolled by varying the period of opening of the 
suction valves and therefore the quantity of fuel 
pumped to each cylinder. 

Structural Details .—Concerning the struc¬ 
tural details, the engine bedplate is in three cast- 
iron sections bolted together, each section con¬ 
taining three main bearings consisting of a flat- 
bottom castiron piece supported in the bedplate 
saddle, a lower main bearing, brass, cored for 
water circulation and capable of being rolled out 
of the saddle without the removal of the crank- 


76 GAS AND OIL ENGINE HAND-BOOK 

shaft, and a flat-topped upper bearing of brass, 
cored out for stiffness and lightness. 

The binding cap is of forged steel and the 
bearing brasses are lined with a white metal con¬ 
sisting of 80 per cent tin, 15 per cent antimony, 
and 5 per cent copper. This metal is somewhat 
harder than the Navy Standard bearing metal. 
The main crankshaft is in three interchangeable 
sections, approximately 15J4 inches in diameter, 
and is made of special forgings having a tensile 
strength of 71,000 to 78,000 pounds, with an 
elongation of 18 to 20 per cent. The sections are 
bored hollow and drilled for the forced lubrica¬ 
tion system. The sequence of cranks (turning 
outboard), are numbers 6, 1, 4, 5, 2 and 3. The 
piston rod, as will be seen from Figure 13e, is 
forged steel and is bored hollow for the passage 
of the fresh cooling water to and from the work¬ 
ing piston. 

Piston .—The piston is divided into two parts 
—the working piston, which consists of a special¬ 
ly lined casting cored for water circulation and 
ribbed for strength, and a lower iron casting, 
which is bolted to the piston rod. The two sec¬ 
tions are not bolted to each other, although both 
are secured to the rod. The working piston is 
dished on top and is machined with greater clear¬ 
ance at its top than at its bottom. It carries 
six cast-iron snap rings varying in width from 
the top to the bottom, the upper rings being 
given more clearance than the lower ones on 
account of the greater heat. The lower part 


GAS AND OIL ENGINE HAND-BOOK 


77 


of the main piston merely serves as a guide and 
has two cast-iron snap rings at the bottom to 
prevent the escape of gas into the engine room. 

Fresh water coming up from the rod enters the 
central compartment of the piston, passes out 
toward the side through cored passages at the 
top of the piston and finally the concentric 
space in the piston rod through four pipes set at 
45 degrees, returning from the highest point 
of the water space and thus insuring a flow 
of water along the hottest parts of the piston. 
This method of conveying the cooling medium 
to and from the piston has the advantage of 
simplicity, but it also has the disadvantage of 
heating the water entering the piston by that 
just leaving the piston, and vice versa. 

The fresh cooling water is drawn from a 
compartment in the double bottom, where it is 
cooled, to the piston, through a swivel joint on 
the after beam bearing, a pipe secured to the 
beam, another swivel joint on the crosshead end 
of the beam, the main crosshead, a nickel-steel 
pipe running up the center of the piston rod, 
and four collecting pipes reaching the highest 
part of the outer cooling space in the piston, as 
previously explained. From the piston rod the 
hot water reaches a discharge main back of the 
engine via links and beams, and the forward end 
of the crosshead, in a manner similar to that of 
entering. 

A small copper pipe leading from the dis¬ 
charge side of each piston i & led to the inboard 


78 GAS AND OIL ENGINE HAND-BOOK 

side of column No. 2, where it delivers through 
a small pet-cock into a funnel. This affords the 
operator an opportunity to see at a glance 
whether the system is functioning properly, and 
he can also feel the temperature of the cooling 
water. 

Cylinder .—The main cylinder is made up of 
two parts—a cast-iron jacket carrying the ex¬ 
haust belt and a plain cylindrical liner of spe¬ 
cial cast iron. The space between the cylinder 
jacket and the liner forms the water jacket for 
the salt cooling water. The top of the liner is 
securely held in place by the cylinder head, while 
the lower end is free to expand through the 
stuffing-box in the bottom of the jacket, which 
prevents salt-water leakage. The surface of 
the liner passing through the tight fit at the 
exhaust belt has several shallow grooves, whose 
obj ect is to collect any slight water leakage. The 
grooves are about one-quarter inch deep and 
one-half inch wide, and are connected to pet- 
cocks on the outside of the cylinder jacket. These 
are kept open and act as leak indicators. 

The cylinder head is bolted to the cylinder 
by 12 studs, the joint between the head and 
the liner being made tight by a thin copper 
gasket. The head has five openings to receive 
the valve cages. The center one is for the fuel 
valve, the two largest openings on either side 
are for the scavenging valves; the inboard open¬ 
ing is for the cylinder-release valve, and the out¬ 
board opening is for the air-starting valve. The 


GAS AND OIL ENGINE HAND-BOOK 


79 


water from the cylinder jacket is bypassed around 
the cylinder-head joint into the lower compart¬ 
ment of the head, through which it must all go 
before rising to the upper compartment. A cast- 
steel sleeve in the center of the head receives the 
spray-valve body. 

The fuel-spray valve located in the center of 
the head consists of a cast-iron body, housing a 
long forged-steel needle valve opening upward. 
This valve is opened by the camshaft and is ordi¬ 
narily held shut by heavy springs. The com¬ 
pressed air for fuel injection is connected to the 
valve body at the top and maintains a constant 
pressure in the body, there being a safety valve 
in the air line at each cylinder. 

The camshaft is on the inboard side of the 
engine and is in four sections, the first section 
carrying the cams for cylinders Nos. 1 and 2; 
the second the governor, the cam for cylinder 
No. 3 and an eccentric for driving the fuel pump 
for cylinders Nos. 1 and the third carries the 
cam for cylinder No. 4 and the gear that trans¬ 
mits the motion of the vertical shaft to the cam¬ 
shaft; and the fourth carries the cams for cylin¬ 
ders Nos. 5 and 6. 

The high-pressure air system consists of the 
three attached air compressors, the spray flask of 
about 5 cu. ft. capacity, the six starting-air 
flasks with a capacity of about 180 cu. ft., air 
separators, piping, release valves, etc. One aux¬ 
iliary air compressor independently driven by 
steam, with a capacity equal to that of one of 


80 


GAS AND OIL ENGINE HAND-BOOK 


the attached air compressors, is also provided 
for charging the spray and starting flasks when 
all the air is gone. 

The salt-water cooling system consists of two 
attached plunger pumps under the middle scav¬ 
enger pump and an independently driven steam 
plunger pump, together with the necessary con¬ 
nections and piping. Both attached pumps have 
a common suction, and each is of sufficient capac¬ 
ity to supply the salt-water system at normal 
power. The salt water is discharged into a large 
main at the back of the engine beneath the floor- 
plate, from which a branch leads upward to the 
bottom of each intercooler for the high-pressure 
air compressors, and to the bottom of each cooler 
in the scavenger-pump castings. The main then 
continues around the forward end of the engine, 
where a branch leads upward on the outboard 
side of the main bearing cap. Continuing around 
to the inboard side of the engine under the floor- 
plate the main supplies a branch to the bottom 
of each ahead crosshead guide. A collecting main 
runs around the engine at the height of the cyl¬ 
inder base. On the inboard side it receives the 
return cooling water from the crosshead guides, 
and at the after inboard side it receives the return 
cooling water from the main bearing and thrust 
block. On the outboard side of the engine it 
receives the cooling water from the scavenger 
cooler. 

Back of the engine all the water in the col¬ 
lecting main enters the bottom of the main cyl- 


GAS AND OIL ENGINE HAND-BOOK 


81 


inder jackets, two branches leading to each 
jacket. The cooling water leaving the high- 
pressure intercoolers of each compressor is led 
to the lower end of the jacket of the middle- 
stage air-compressor cylinder. From here it is 
forced upward into the jacket of the low-stage 
cylinder through two ferrules set partly into 
each cylinder at the joint. From the low-stage 
jacket the water enters the high-stage jacket 
through two by-passes around the cylinder joint, 
and from the high-stage jacket the water is 
forced into the high-stage cylinder head to two 
bypasses around the joint between the head and 
the cylinder. From the head of each high-stage 
cylinder the water is led into the exhaust-pipe 
jacket. From the main cylinder jacket the water 
enters the cylinder head through a bypass around 
the joint between the cylinder and the head. 
After circulating through the lower and upper 
compartments of the head, the water enters the 
exhaust-pipe water jacket, and from here is finally 
discharged into an overhead discharge main. 

Operation .—On the operator’s platform is the 
maneuvering control wheel, which controls the 
starting, stopping and reversal of the engine by 
means of compressed air. This wheel also cuts 
off the fuel and spray air from the cylinders 
during maneuvering and until the engine is turn¬ 
ing over in the desired direction. Above the 
maneuvering control is a dial on which a pointer 
indicates the running position of the engine. 

On the forward side of No. 4 column is 1:he 


82 


GAS AND OIL ENGINE HAND-BOOK 


fuel-control wheel, which governs the quantity 
of fuel pumped into each cylinder. The pointer 
and dial above the fuel control indicate in eight 
equal steps the quantity of fuel pumped, from 
a minimum to the maximum. Coming out from 
the shaft of the fuel-control wheel is the needle- 
stroke control which varies the stroke of the fuel- 
spray needle from maximum to minimum. 

On the after side of column No. 3 is a hand 
cutout by which the engine can be instantly 
stopped. It operates to raise the suction valves 
of the fuel pumps, thus rendering them inoper¬ 
ative. Below this is the control for the high- 
pressure air supply, which regulates the opening 
of the suctions of the low-stage cylinders of the 
air compressors. The quantity and the pressure 
of the spray air is thus controlled. 

Dry Batteries. In one respect dry bat¬ 
teries have a decided advantage over liquid bat¬ 
teries for ignition purposes, from the fact that on 
account of their high internal resistance they can¬ 
not be so quickly deteriorated by short circuiting. 

On account of the high internal resistance, dry 
batteries will not give so large a volume of cur¬ 
rent as liquid batteries, but a set of dry batteries 
may be short circuited for five minutes without 
apparent injury and will recuperate in from 
twenty to thirty minutes, while a liquid battery 
would in all probability be badly deteriorated 
under the same conditions. 

A dry battery of the usual type consists of a 


GAS AND OIL ENGINE HAND-BOOK 83 


zinc cell which forms the negative element of the 
battery. The electrolyte is generally a jelly-like 
compound containing sal-ammoniac, chloride of 
zinc, etc. The carbon or positive element is 
enclosed in a sack or bag containing dioxide of 
manganese and crushed coke, which are the 
depolarizing agents of the battery. 

Dynamometer. A dynamometer is a form of 
equalizing gear which is attached between a 
source of power and a piece of machinery when 
it is desired to ascertain the power necessary to 
operate the aforesaid machinery with a given rate 
of speed. 

Efficiency, Mechanical. The mechanical 
efficiency of a gas or oil engine depends on its 
design, workmanship and proper lubrication, and 
also on: 

The proper mixture of air and fuel. 

The correct degree of compression. 

The correct point of ignition. 

The duration and completeness of combus¬ 
tion. 

The rapidity and amount of expansion. 

Efficient governing and free exhaust. 

If any doubts exist as to the engine giving out 
its proper power, a brake test should be made. 

To ascertain the mechanical efficiency of a ga ? 
or oil engine, both indicator and brake horse¬ 
power tests should be made, and if I.H.P. be 
the indicated horsepower and B.H.P. the actual 


84 GAS AND OIL ENGINE HAND-BOOK 


of brake horsepower of the engine and M.E. be 
its mechanical efficiency, then 


M.E. 


B.H.P. 

I.H.P. 


If the brake horsepower of an engine be 7.5 
and the indicated horsepower be 10, then the 
mechanical efficiency will be 


ME --W 


which equals 75 per cent. 

In te> t-books the efficiency of an engine is 
usually considered as the relation between the 
heat-units consumed by the engine and the work 
or energy in foot-pounds given out by it. If the 
heat-unit s (which are measured by the quantity 
of fuel si pplied to the engine) be large compared 
to the work or energy given out by the engine, 
its efficiency is small. 

Efficiency, Thermal. The ratio of the heat 
utilized by the engine, as shown by the power 
developed, as compared with the total heat con¬ 
tained in the fuel absorbed by the engine, is 
known as the thermal efficiency. This can be 
obtained by the following formula: 

Let F=consumption of fuel in pounds per 
brake horsepower per hour, and 

C = calorific value of the fuel per pound in 
heat units, then 

_ 42.63 X 60 


C X F 




GAS AND OIL ENGINE HAND-BOOK 


85 


The thermal efficiency of the gas engine is low 
as compared with the oil engine. The best gas 
engine makers now claim a thermal efficiency for 
their engines of 27 per cent, whereas recent tests 
of the Diesel oil engine show a thermal efficiency 
of 30.3 per cent. 

Electricity, Forms of. Electricity or elec¬ 
trical energy may be generated in several ways— 
mechanically, chemically and statically or by 
friction. By whatever means it is produced, 
there are many properties which are common to 
all. There are also distinctive properties. The 
current supplied by a storage battery will flow 
continuously until the battery is practically ex¬ 
hausted, while the current from a dry battery can 
only be used intermittently: that is, it must have 
slight periods of rest, no matter how short they 
may be. 

The dynamo or magneto current is primarily 
of an alternating nature or one which reverses its 
direction of flow rapidly. In use, this alternating 
current is changed into a direct or continuous 
current flowing in one direction only, by means 
of a commutator. Any of the forms described 
are capable of igniting an explosive charge in a 
motor cylinder, but the static or frictional form 
of electricity is not used for this purpose on 
account of its erratic nature. 

Electric Light Outfits. Although gas and oil 
mgines for electric lighting purposes are of 


86 GAS AND OIL ENGINE HAND-BOOK 


special design, the lights may sometimes flicker. 
Flickering in the incandescent lights may be 
located by close inspection of the engine and 
dynamo, and may be due either to the flywheels, 
the governor or the belt. To locate this defect 
and remedy it, notice the lamps carefully. If the 
variations in the light are due to lack of weight 
in the rim of the flywheel, these variations will 
be seen to coincide with the revolutions of the 
engine. Again, if the variation in the lights is 
only periodical, then this defect should be 
remedied by adjustment of the governor. Exam¬ 
ine the governing mechanism of the engine. 
If the variation is caused by the governor acting 
too slowly, then adjust the governor so as to 
cause more rapid action upon the controlling 
mechanism. 

The cause of the trouble may not be, as 
already suggested, in the flywheel or in the 
adjustment of the governor, but in the belt, 
which is frequently the sole cause of flickering in 
the lights. The engine and dynamo pulleys over 
which the belt runs should be exactly in line with 
each other. The belt should be made endless, 
or if jointed the joints should be very carefully 
made. A thick, uneven joint in the belt will 
cause a flicker in the lights each time it passes 
over the dynamo pulley. 

Figure 14 shows a two-cycle gasoline engine 
directly connected to a dynamo, both engiile 


GAS AND OIL ENGINE HAND-BOOK 87 


and dynamo being mounted on a cast iron 
base. 

To secure a steady light with gas or oil 
engines, the practice has been to place a flywheel 
upon the dynamo shaft, as the speed of some 
engines sometimes varies as much as 5 per cent. 
The constructional details of some gas engines 



FIG. 14 

Electric light outfit, showing two-cycle engine direct-connected 
to dynamo. 


used for this purpose have been so considerably 
improved that the dynamo flywheel is not consid¬ 
ered necessary. 

This uniform speed has been largely secured 
by increasing the diameter and weight of the 
flywheels, together with an improved method of 
direct balancing, the balance being fitted to the 







































88 


GAS AND OIL ENGINE HAND-BOOK 


crank, instead of to the rim of the fly-wheel, 
which is usually the case with ordinary engines. 
A very sensitive governing gear, however, is 
necessary. In connecting up the exhaust pipe 
it should be run directly to the atmosphere with 
as few turns as possible. 



Improper exhaust connection. 

It is always wise to bush the exhaust pipe to 
a size larger than the size of the opening of the 
cylinder. It is said that about sixty-five feet of 
exhaust pipe laid in a straight line tend to create 
a vacuum in the cylinder the moment after the 
exhaust valve opens. 

This may be true for some engines, but it 














GAS AND OIL ENGINE HAND-BOOK 89 


certainly would be a disadvantage in an engine 
governed by holding the exhaust valve open, as 
in such cases the exhaust gases are alternately 
sucked into and expelled from the cylinder dur¬ 
ing the idle strokes. 



Figure 15 illustrates an improper method of 
connecting up the exhaust pipe. The end of 
the pipe exposed to the atmosphere is liable to 
collect rain or snow and lead it down to the 
cylinder when the engine is idle. 



















90 


GAS AND OIL ENGINE HAND-BOOK 


Figure 16 illustrates the proper method of 
connecting the exhaust pipe. If the noise of the 
exhaust is not objectionable, the exhaust vessel 
may be dispensed with and a bushing put on the 
lower end of the exhaust pipe, which may be 
fitted with a stop cock. This is left open when 
the engine is idle, allowing any water to escape. 
Where the noise is objectionable the exhaust 
pipe may be led into an underground chamber 
of several cubic feet capacity. This pit may 
be partly filled with broken stone and connected 
to the atmosphere by a large pipe. Such a 
device will most effectually muffle the exhaust. 
The pit should be provided with a pair of light 
iron doors on top, which will open in case there 
should be an explosion of unb.urned gases es¬ 
caped from the cylinder. Exhaust pipes should 
never be led into brick chimneys. 

The danger of explosions of unburned gases 
is greatly increased by leading the exhaust into 
a brick chimney. 

Smoke coming from the exhaust of a gas or 
oil engine is due to one of two conditions: Over¬ 
lubrication—too much lubricating oil being fed 
to the cylinder of the engine, or too rich a mix¬ 
ture; that is, too much fuel and an insufficient 
supply of air. 

The first condition may be readily detected by 
the smell of burned oil and a yellowish smoke. 
The second, by a dense white smoke, accom¬ 
panied by a pungent odor. 


GAS AND OIL ENGINE HAND-BOOK 91 


Exhaust Valve, Leaky. Considerable 
trouble is often experienced from this source, 
owing to the action of the intense heat of the 
exhaust gas on the valve and its seat. This valve, 
especially if made of common steel, is apt to cor¬ 
rode and become pitted. Improvements in valve 
construction and more effective cooling of the 
exhaust valve seat have, however, eliminated 
much of this trouble; in fact, with late construc¬ 
tions, the occasional inspection of the valves is 
more a matter of precaution than a necessity. 


Explosions in the Inlet-pipe. These usually 
only occur in engines with mechanically operated 
inlet-valves, a weak or a too rich charge of 
explosive mixture being ignited burns slowly in 
the combustion chamber and when the piston has 
reached the end of the exhaust stroke and the 
inlet-valve commences to rise, the burning gases 
in the combustion chamber ignite the explosive 
mixture in the inlet-pipe. 

A further loss arises from this kind of explo¬ 
sion, as on the next admission or suction stroke 
these partly burned gases enter the combustion 
chamber, instead of an entirely fresh supply of 
gas and air, and consequently retard the com¬ 
bustion and reduce the power of the next explo¬ 


sion. 


92 GAS AND OIL ENGINE HAND-BOOK 


Explosions, Weak. These may be caused 
from improper mixture, ignition set too late, loss 
of compression from defective piston, valves, or 
joints. 

Fire Insurance. The following are the gen¬ 
eral requirements of the various boards of fire 
underwriters for the installation and use of oil 
engines: 

Location of Engine. Engine shall not be 
located where the normal temperature is above 
95 degrees Fahrenheit-, or within ten feet of any 
fire. 

If enclosed in room, same must be well venti¬ 
lated, and if room has a wood floor, the entire 
floor must be covered with metal and kept free 
from the drippings of oil. 

If engine is not enclosed, and if set on a wood 
floor, then the floor under and three feet outside 
of it must be covered with metal. 

Oil Feed Tank. If located inside of build¬ 
ing, shall not exceed five gallons capacity, and 
must be made of galvanized iron or copper, not 
less than No. 22 B. & S. Gauge, and must be 
double seamed and soldered, and must be set in 
a drip pan on the floor at the base of the 
engine. 

Fire Pot or Muffler. Gas or oil engines hav¬ 
ing a relief-exhaust in the form of a port or 
opening, which is uncovered by the piston shortly 
before the end of the explosion or working stroke 


GAS AND OIL ENGINE HAND-BOOK 93 


of the engine, should have the fire pot or muffler 
connected with the relief-exhaust port opening 
and a separate pipe provided for the regular 
exhaust valve opening. If this is not done, back 
pressure from the relief-exhaust will oppose the 
free discharge of the exhaust gases from the main 
exhaust valve, thereby causing an excessive 



FIG. 17 

Muffler installation, showing muffler connected to relief-exhaust 
on left-hand side of engine. 


amount of the products of combustion to be left 
in the cylinder at the termination of the exhaust 
stroke. Figures 17 and 18 show methods of 
attaching the fire pot or muffler to the relief- 
exhaust on the left and right-hand sides of the 
engine respectively. The main exhaust connec¬ 
tion is omitted in Figure 18. 




























94 GAS AND OIL ENGINE HAND-BOOK 

Flash Test of Oils. The apparatus used for 
this purpose consists of a small copper vessel in 
which the oil to be tested is placed. This vessel 
is immersed in a larger vessel containing water, 
which forms part of the upper portion of the 
apparatus. 

A thermometer is suspended with its lower 



FIG. 18 

Muffler installation, showing muffler connected to relief-exhaust 
on right-hand side of engine. 


part in the oil. A heating lamp placed under 
the receptacle containing the water raises the 
temperature of both water and oil as required. 
A lighted taper is passed to and fro over the top 
of the oil as it becomes heated. When the vapor 
given off by the oil flashes the temperature is 
noted, and that is termed the flashing point of 
the oil tested. 


























GAS AND OIL ENGINE HAND-BOOK 95 


Flywheels. The flywheels of a gas or oil 
engine require careful keying on the crank shaft. 
If the keys are not a good fit and are not driven 
home properly the engine may knock when run¬ 
ning. Two keys are usually fitted to the shaft of 
large engines, one being a feather key, which is 
fitted in a keyway in the shaft as well as in a 
keyway cut in the flywheel hub, the second key 
being a taper key with a gib-head, which is 
recessed in the flywheel hub and made concave 
on the lower side to fit the shaft. 

Weight of Rims of Flywheels. The weight 
of the rim of the flywheel is the only portion 
which enters into the following calculations, the 
weight of the web or spokes and hub being 
neglected. 

Let M.P be the mean pressure of the com¬ 
pression, and A the area of the piston in square 
inches. If S be the stroke of the piston in 
inches, and N the number of revolutions per 
minute of the engine, let D be the outside diam¬ 
eter of the flywheel in inches and W its required 
weight in pounds, then 

TTT M.P X A X S X N 
2560 X D 

Diameter of Rims of Flywheels. An 
engine that is intended to operate at a slow rate 
of speed and consequently with a high degree of 
compression, will require a flywheel of much 



96 GAS AND OIL ENGINE HAND-BOOK 


greater diameter and weight than a higher speed 
engine of the same bore and stroke. It may be 
well to remember that within certain limitations 
the diameter and weight of a flywheel should be 
as small as is possible, as an increase in either 
means a reduction in engine speed, increased 
friction and a consequent loss of power. 

To ascertain the proper diameter of a flywheel 
when all other conditions are known, if D be the 
required diameter of the flywheel in inches, then 

_ M.P X A X S X N 
2560 X W 

Two flywheels should be used for steady run¬ 
ning, at the same time, they equalize the wear on 
the crank-shaft bearings. They should be care¬ 
fully turned and balanced, and run perfectly true 
at full speed. If one wheel is used, it should be 
of heavy construction and supported by an out¬ 
side bearing. 

Foundation Bolts. The number and size of 
these are usually determined by the builder of the 
engine and indicated by the number of holes in 
the engine base. The bolts should be long 
enough to extend from the bottom of the founda¬ 
tion to from two and a half to four inches above 
the capstone. 

They should have iron anchor plates at the bot¬ 
tom and be threaded at the top to receive a 
nut. 



GAS AND OIL ENGINE HAND-BOOK 97 


Three or four days after the foundation is 
completed, and the cement firmly set, the engine 
may be placed in position and bolted down ready 
for work. 

Foundations. A concrete foundation, if prop¬ 
erly constructed, is the best. While founda¬ 
tions are usually built of brick or stone laid in 
cement, a foundation may be of concrete, mixed 
as follows: One part of cement, two parts of 
coarse sand, five parts of fine crushed stone or 
coarse gravel. 

It is desirable to have the capstone from 3 to 
6 inches wider and longer than the base of the 
engine. The depth of the foundation will depend 
entirely upon the condition of the ground in the 
vicinity where the engine is to be set up. 

The foundation should always go below the 
freezing line and as much below as is necessary 
to get a firm base. Ordinarily from 3 to 4 feet 
is sufficient for small engines of from 4 to 
12 horsepower. For larger engines from 15 
to 40 horsepower, 4 to 6 feet is not too much. 

Where possible, the sides of the foundation 
should have a slope or batter not less than 
15 degrees. 

Four-cycle Engine, Construction of. The 

general construction of a four-cycle gas or oil 
engine is plainly shown in Figure 19. The 
engine is equipped with both hot tube and elec¬ 
tric ignition and an atmospherically or suction 


98 GAS AND' OIL ENGINE HAND-BOOK 

operated inlet-valve. Reference to the table and 
the corresponding letters in the drawing will give 
a clear understanding of the use of the various 
parts of the engine. 



FIG. 19 

Vertical longitudinal section of four-cycle motor, showing con¬ 
structional details. 


A—Crank Case. 

B—Cylinder. 

C—Crank Shaft. 

D—Connecting-rod. 

E—Piston. 

F—Piston Wrist Pin. 

G—Upper Hand Hole Plate. 
H—Lower Hand Hole Plate. 
J—Oil Test Plug. 

K—Drain Plug. 

L—Splash lubricator. 


M—Crank Pin bearing Ad¬ 
justing Nut. 

N—Crank Pin bearing Lock 
Nut. 

O—Cylinder Oiler. 

P—Ignition Tube. 

R—Admission Valve. 

T—Piston-rings. 

U—Inlet for cooling water. 
V—Outlet for cooling water. 


Four-cycle Engine, Operation of. A four¬ 
cycle engine has only one working stroke or 
impulse for each two revolutions. During these 


















GAS AND OIL ENGINE HAND-BOOK 99 


two revolutions which complete the cycle of the 
engine, six operations are performed: 

1. Admission of an explosive charge of gas or 
gasoline vapor and air to the cylinder of the 
engine. 

2. Compression of the explosive charge. 

3. Ignition of the compressed charge by a hot 
tube or an electric spark. 

4. Explosion or extremely sudden rise in the 
pressure of the compressed charge, from the 
increase in temperature after ignition. 

5. Expansion of the burning charge during the 
working stroke of the engine piston. 

6. Exhaust or expulsion of the burned gases 
from the engine cylinder. 

As pressure increases with a rise in tempera¬ 
ture, which in an engine the moment after 
ignition has taken place is about 2,700 degrees 
Fahrenheit, the higher the temperature of the 
ignited gases, the greater would be the pressure. 
As this pressure is expended in work on the 
engine piston, the whole of it might, if expansion 
of the burning gases were continued long enough, 
be utilized. Full utilization of the expansion of 
the gases is impossible from a mechanical point 
of view. The expansion of the gases should be 
as rapid as possible, as the faster the piston 
uncovers the cylinder wall, the less time will be 
left for the transmission of heat or energy to the 
cylinder wall. Gasoline vapor or gas in them- 


100 GAS AND OIL ENGINE HAND-BOOK 

selves are not combustible, but must be mixed 
with a certain amount of air before ignition and 
consequent combustion can be effected. The 
combustion of the gases is not instantaneous, but 
continues during the entire working stroke of the 
engine piston. 

Four-cycle Engine, Principle of. Figure 20 
gives four diagrammatic views of the operation of 
a four-cycle gas or oil engine. It shows an inlet- 
valve A, valve-openings B, cylinder C, cam D, 
exhaust valve E, combustion chamber F, piston 
G, valve springs H, crank case J, connecting-rod 
K and crank-pin L. 

Diagram No. 1 shows the piston about to draw 
in a charge of explosive mixture, the suction or 
drawing in of the charge continues until the 
piston has reached the position shown in Diagram 
No. 2. Then the piston returns until it arrives 
at the position shown in Diagram No. 3, com¬ 
pressing the charge of mixture during this opera¬ 
tion. Just before the piston has reached the end 
of its travel in this direction, the charge under 
compression is ignited either by an incandescent 
tube or by an electric spark and the force of the 
explosion drives the piston back to the position 
shown in Diagram No. 4, when the exhaust-valve 
is opened by means of the cam and valve-lifter 
rod. The exhaust valve remains open until the 
piston has reached the position shown in Dia¬ 
gram No. 1. Then it closes, the piston again 


GAS AND OIL ENGINE HAND-BOOK 101 



FIG. 20 

Four-cycle motor diagram, showing the various operations dur¬ 
ing the cycles. 




















102 GAS AND OIL ENGINE HAND-BOOK 


commences to draw in a charge of explosive mix¬ 
ture and the cycle of operation of the engine is 
repeated. As it requires four strokes of the 
piston or two complete revolutions of the crank 
shaft to complete the cycle, there is consequently 
only one impulse every two revolutions or one 
working piston stroke out of four. 

Four-cycle Marine Engines. A single-cylinder 
four-cycle engine is shown in Figure 21 This 
style of engine may be used for either marine or 
automobile work, being light in weight, simple in 
construction and made in sizes from to 10 
horsepower. 

A two-cylinder engine of similar construction 
to the one just described is illustrated on the 
front page of this Work. These engines are from 
9 to 20 horsepower. Such engines are being 
greatly used for motor launches on account of 
their light weight and great power. 

Friction Clutches. When fast-and-loose pul¬ 
leys or friction clutches are used the advantages 
gained are: the ease with which the engine can 
be started, the loose pulley or friction clutch 
only, instead of the whole line shaft, has to be 
turned when the plant is started, and in case of 
accident or other emergency necessitating the 
quick stopping of the revolving machinery, this 
can be accomplished at once by simply moving 
over the lever of the friction clutch or tight-and- 
loose pulleys. Otherwise the heavy flywheels of 


GAS AND OIL ENGINE HAND-BOOK 103 


the engine would keep revolving for some time 
after the fuel supply of the engine is shut off, and 


















































































104 GAS and oil engine hand-book 

being directly connected by belt to the shafting 
and machinery, the whole plant is in motion as 
long as the flywheels keep revolving. 

Fuel Consumption of Gas and Oil Engines. 
The fuel consumption of an engine is always one 
of grave importance to the purchaser, as well as 
to the manufacturer. 

Ordinarily about ly\ pints of gasoline or 
about 15 feet of natural gas, per horsepower per 
hour under full load, will cover the fuel con¬ 
sumption. That is, when the fuels used are of 
standard quality and the water comes from the 
water jacket at a temperature of about 140 
to 160 degrees Fahrenheit. 

The temperature of the water in the jacket 
around the cylinder has a great deal to do with 
fuel consumption. 

To economize on the fuel consumption of an 
engine the following points should be observed: 

1. To keep the jacket water at 160 degrees 
Fahrenheit. 

2. To run the engine at a medium speed. 

3. To use a good standard grade fuel. 

4. To see that every charge the engine takes is 
exploded, for which a proper mixture and a good 
spark or hot tube are necessary. 

5. The admission valve should close properly 
between charges, so as not to allow a continuous 
flow of fuel into the engine. 

6. Never throttle the fuel so closely that the 


GAS AND OIL ENGINE HAND-BOOK 105 


engine cannot get a full charge every time it 
needs it. 

7. Be sure that there is no leak in the supply 
or overflow pipes where fuel can escape. 

8. When gasoline or kerosene is used, be sure 
that there is no leak in the supply tank. 

9. See that the exhaust and inlet valves seat 
properly and do not leak. The piston-rings 
should hold the pressure due to the explosion. 

Fuel Gas Oil. An oil known as fuel gas oil is 
procured in the process of fractional distillation 
after the lighter oils and the illuminating oil? 
have been taken off. Tests of samples of this 
fuel gas oil, the characteristics of which vary con¬ 
siderably, are given in the following table: 

FUEL GAS OIL. 

Specific gravity. 0.832 .878 

Beaume. 36° 30.2° 

Flash-point. 144° F. 298° F. 

Fire test. 183° F. 247° F. 

This fuel is much used in oil engines in the 
United States. With the heavier grades a slight 
deposit of carbon is left in the engines, which 
requires periodical removing. 

Gas Bag. The gas bag of a gas engine 
should be entirely of vulcanized rubber, or it 
may be made with an iron frame and rubber 
sides. 

The gas bag serves its purpose better the 
nearer it is to the engine. As the pulsating of 






106 GAS AND OIL ENGINE HAND-BOOK 


the bag endangers its pulling off the pipe, care 
should be taken to secure the openings of the 
bag to the pipe by winding soft iron or copper 
wire around them. 

As oil destroys rubber and changes it into a 
sticky, viscous mass, the gas bag should be 
placed out of reach of any oil which might be 
liable to splash upon it. 

Gases, Expansion of. All gases expand 
equally, part of their volume for each degree 
of temperature, Centigrade, or part of their 
volume for each degree of temperature, Fahren¬ 
heit. 

Gasoline, How Obtained. Gasoline, ben¬ 
zine, naphtha and the kindred hydrocarbons are 
the products of crude mineral oil. 

They are separated from the crude oil by a 
process of distillation. The process is very sim¬ 
ilar to that of generating steam from water. 

By the application of heat, water raised to a 
temperature of 212 degrees Fahrenheit changes 
from a liquid to a gaseous state, called steam. 
This conversion is only temporary. If steam is 
confined and cooled to a certain point it will 
quickly return to its liquid state, water, by the 
process known as condensation. 

Crude mineral oil subjected to heat will give 
off, in the form of vapor, such products as gaso¬ 
line, benzine, naphtha, etc. The degrees of 
heat at which these products are separated are 


GAS AND OIL ENGINE HAND-BOOK 107 


comparatively low. Various degrees of heat will 
separate the distinct products. As a means of 
illustration, say that crude oil raised to a temper¬ 
ature of 110 degrees gives off vapor which when 
cooled will liquefy into what is known as naphtha, 
benzine at 125 degrees, and gasoline at 140 
degrees. These degrees of temperature are not 
authentic—simply used to illustrate. 

After these lighter products are separated there 
yet remains the thick, oily liquid from which the 
various lubricating oils are prepared. 

Kerosene oil is one of the principal products of 
crude oil, and the oily sediment which frequently 
accumulates in the bottom of the tank or can in 
which gasoline is confined is kerosene oil, which 
distills over in small quantity with the vapor of 
gasoline. 

Gasoline or Kerosene Fires. In case of fire 
due to gasoline or kerosene, use fine earth, flour 
or sand on top of the burning liquid. Never 
use water, it will only serve to float the gasoline 
or kerosene and consequently spread the flames. 

A dry powder can be used for this purpose 
which will extinguish the fire in a few seconds. 
It is made as follows: Common salt, 15 parts— 
sal-ammoniac, 15 parts—bicarbonate of soda, 
20 parts. The ingredients should be thoroughly 
mixed together and passed through a fine mesh 
sieve to secure a homogeneous mixture. 

If by any chance a tank of gasoline or kero- 


108 GAS AND OIL ENGINE HAND-BOOK 


sene takes fire at a small outlet or leak, run to 
the tank and not away from it, and either blow 
or pat the flame out. Never put water on burn¬ 
ing gasoline or kerosene, the gasoline or kerosene 
will float on top of the water and the flames 
spread much more rapidly. Throw fine earth, 
sand or flour on top of the burning liquid. Flour 
is best. The best extinguisher for a fire of this 
kind in a room that may be closed, is ammonia. 
Several gallons of ammonia, thrown in the room 
with such force as to break the bottles which 
contain it, will soon smother the strongest fire if 
the room be kept closed. 

Gasoline explosions are often due to a pressure 
within a tightly-closed container, caused by high 
temperature, which vaporizes or gasifies the liquid 
within. 

The changing of the liquid to the gaseous state 
causes expansion, and if there is no vent or safety 
valve connection the pressure within rises to a 
point sufficient to cause an explosion. 

Gas Producer. Producer gas, whether from 
anthracite or bituminous coal, lignite, wood, 
charcoal, or coke, is remarkably uniform in 
quality, and a very desirable gas, if properly 
cleansed from dust, tar and sulphur. As prac¬ 
tically all the combustible matter of coke and 
charcoal is fixed carbon, these fuels are most 
readily gasified, and on this account are favorite 
fuels for small gas plants of the suction pro¬ 
ducer type. 


GAS AND OIL ENGINE HAND-BOOK 109 

Anthracite coal contains a small quantity of 
volatile matter, but is also a very desirable fuel, 
the gas requiring but little cleaning. Bituminous 
coal, lignite and wood, although giving a de¬ 
sirable power gas, at the same time yield consid¬ 
erable amounts of hydro-carbon vapors, con¬ 
densible in the form of tar and pitch, the re¬ 
moval of which from the gas is attended with 
some difficulty. 

Complete producer gas plant equipments may 
be had of several types, suited either to bitumi¬ 
nous or non-bituminous fuels, and with or with¬ 
out apparatus for the reclamation of by-prod¬ 
ucts, such as ammonia, tar and other hydro¬ 
carbons. The majority of these systems are 
simple in construction and operation, and yield 
a net efficiency considerably in excess of the 
steam boiler plant. 

In localities where natural gas is not avail¬ 
able, the producer gas plant affords a compara¬ 
tively simple and inexpensive means of generat¬ 
ing a suitable fuel gas. 

The gas producer takes the coal, ignites it,, 
and by supplying a limited amount of air, and 
a proportionate amount of water, keeps the fire 
at a dull red glow, just the right temperature 
to produce a good uniform quality of gas and 
prevent formation of clinkers. As the load on 
the engine is varied, a greater or lesser quantity 
of gas is required, but it is important that the 
quality or heat power remain the same. 

At present three distinct types of gas pro- 


110 GAS AND OIL ENGINE HAND-BOOK 


ducer are offered to the power user. They are 
the suction producer, the steam-pressure pro¬ 
ducer, and the induced down-draft producer. 

In the suction producer the fuel is fed into 
the generator from a hopper at the top. Ashes 
and clinkers are removed from the bottom, and 
air is usually admitted below the grate, first 
passing through economizers, where it is heated 
and passed over a body of hot water to absorb 
the necessary moisture. In some makes of pro¬ 
ducer the air is admitted direct from the engine 
room, and a small, regulated amount of water 
is fed into a space prepared around the grate, 
where it is evaporated and is carried as steam 
along with the air up into the fuel bed. 

In this type of producer, coke or anthracite 
coal can only be used, and not even these fuels 
in the very small sizes. It is not easy to note 
the condition of the fire, as the generator cannot 
be opened at the top without admitting air and 
causing a poor mixture of gas; the only thing 
to do in this emergency is to feed in more coal 
to stop the chimney holes in the fire-bed, or 
quickly insert a poker bar and thoroughly tamp 
the fuel. The latter is the better way, even 
though it has to be done blindly. 

In operating this type of producer, trials and 
tribulations may be many and varied, depending 
largely upon how the producer is made and the 
basis of its horse power rating. A suction gas 
producer rated at more than 1^/2 pounds of 
coal per square foot of grate area, or area of 


GAS AND OIL ENGINE HAND-BOOK 111 


fuel-bed cross-section, is very apt to be too 
small, and a producer so small for the power 
it has to develop that it must be driven to fur¬ 
nish sufficient gas will immediately develop 
clinker troubles, variable gas troubles or excess 
C0 2 . If an attempt is made to correct clinker 
troubles with an over-supply of steam an excess 
of hydrogen w T ill result, with its attendant engine 
difficulties of back-firing, or premature ex¬ 
plosions. 

Even with a producer of the proper size, the 
regulation of the volume of steam or water to 
the volume of air must be closely watched. Too 
frequent raking of the fire will waste good fuel, 
and induce draft holes through the fuel bed. Too 
much poking from the top will pack the fire, 
and necessitate an increased vacuum. Too fine 
a fuel will produce the same troubles, and any 
coal that fuses easily will not do for this type 
of producer. Anthracite running high in slate 
mixture tends to run high in sulphur, and high 
sulphur with slate makes bad clinkers at any 
time, and if the fire is forced at all will soon 
necessitate a shutdown to clean out. The pro¬ 
ducer should be of ample size—10 pounds of 
coal per square foot of internal area—and rated 
on 1^4 pounds of coal per horse power hour. 

It is not good practice to use a suction gas- 
producer plant of over 150 horse power when 
the engine has to draw the gas from the pro¬ 
ducer by the vacuum in the cylinder. Sizes 


112 GAS AND OIL ENGINE HAND-BOOK 


larger than this should be equipped with ex¬ 
haust fans, which will relieve the engine of chis 
work, the exhausters being driven by motors or 
other auxiliary power. 



FIG. 22 

Sectional view of Monahan Producer. 


A vertical section of the Monahan suction pro¬ 
ducer as shown in Figure 22, is of the suction 
type, and consists of the usual generator, scrub¬ 
ber and equalizing tank. The vaporizer for sup¬ 
plying steam to the fuel bed is an upper exten- 












































GAS AND OIL ENGINE HAND-BOOK 113 


sion of the generator, but is located so that the 
hot gases from the fuel bed do not impinge 
squarely on the bottom of the vaporizer. This 
is clearly shown in the sectional view, Figure 22, 
in which the revolving grate and air heater are 



FIG. 23 

Steam regulator. 


also shown. The scrubber is of the wet, coke- 
filled type, and the equalizing tank is a simple 
drum within an equalizing chamber formed in 
its cover, and separated from the drum by a 
rubber diaphragm. 

A small vent in the cover allows air to pass in 




















114 gas and oil engine hand-book 

or out slowly, forming a sort of brake on the 
fluctuations of pressure within the drum. The 
regulator controlling the admission of steam to 
the fuel bed is shown in section in Figure 23. 
The outlet at the bottom is connected to the 
ash pit of the generator. The upper intake 
admits air only, and the intake near the middle 
admits steam. When running light the suction 
is insufficient to pull down the valve, and air 
alone passes through the fire. As the load in¬ 
creases, the increasing suction gradually pulls 
down the valve (which is a piston valve) until 
the steam ports are uncovered to an extent de¬ 
pending upon the load. This arrangement pre¬ 
vents the chilling of the fire with steam at very 
light loads, and graduates the supply for heavier 
loads. 

The Steam-Pressure Producer. This type has 
an upward draft, the air being drawn in around 
a steam jet through a Korting nozzle of the 
Bunsen type. Anthracite and coke are the only 
kinds of fuel available, unless tar extractors and 
other expensive mechanical auxiliaries are pro¬ 
vided to clean the gas. When the producer is 
equipped with such cleaning apparatus, bitumi¬ 
nous coals or fuels containing volatile hydro¬ 
carbons may be used, but as these are condensed 
and washed out of the gas, the thermal efficiency 
of the producer is reduced to the extent of the 
loss of the heat units contained in the extracted 
hydrocarbons, which are the richest part of the 
fuel. 


GAS AND OIL ENGINE HAND-BOOK 115 

With a pressure producer it is necessary to 
have gas-storage capacity, so that gas-holders 
must be provided regardless of the kind of fuel 
used, and these must hold enough gas to run 
the engine while the fire is being poked and the 
ashes removed. Coal is fed through a tightly 
closing hopper on top of the generator, and 
ashes are removed from the bottom when the 
generator is not in operation. It is almost im¬ 
possible to poke oi bar the fire while the pro¬ 
ducer is running, as any outlet for this purpose 
will be flooded with burning gas escaping under 
whatever pressure the steam jet is maintaining at 
the time. 

Induced Down-Draft Producer. In the down- 
draft producer the gas is drawn down through 
the fire by an exhauster or fan, and forced by 
the exhauster through the main to the point of 
use. There is probably more horse power of 
these producers in use than in all of the others 
put together, but they are mostly of large size 
and the plants only number about one-fourth of 
the total. 

Essentially these are bituminous coal pro¬ 
ducers. They are operated with an open top, 
where the fire is seen by the operator, and any 
blowholes or passages in the fire are easily closed 
by the use of the poker or tamping bar, and 
fresh fuel is fed as necessary. The volatile 
hydrocarbons of the fuel, being distilled at the 
top of the fuel bed, mix with the in-drawn air 
and steam and pass down through the bed of 


116 GAS AND OIL ENGINE HAND-BOOK 


incandescent carbon, where they combine with 
the other gases and leave at the bottom of the 
producer, as a fixed non-condensable gas. The 
combination of gases then passes directly into 
the bottom of a vertical tubular boiler and out 
at the top, thence into the bottom of the wet 
scrubber, where the outlet is under water to form 
a seal and prevent the gas from returning to the 
producer. From the top of the wet scrubber the 
gas passes to the exhauster, and is forced 
through the dry scrubber to the gas-holder. 

The boiler, which is a part of the producer 
installation, supplies a large part of the steam 
necessary for the producer, and also the amount 
necessary to run the engine driving the ex¬ 
hauster. This steam is made from the heat given 
up by the gas in its passage through the. boiler, 
and all heat that is not absorbed by the water 
is delivered up to the wet scrubber. Once a 
week these producers have to be entirely cooled 
down to be cleaned, and as the steam pressure in 
the boiler is down at this time, an auxiliary 
boiler has to be provided to start up again. 
Some time during the week, especially toward 
the last days, the fuel beds become so clogged 
with the accumulation of ashes and clinkers that 
water-gas runs have to be made every few mo¬ 
ments ; the load on the engine driving the ex¬ 
hauster increases, and both these conditions so 
increase the demand for steam that the auxiliary 
boiler has to be brought into use. 

For continuous 24-hour service with this type 


GAS AND OIL ENGINE HAND-BOOK 117 

of producer it is necessary to have a spare unit, 
in order that it can take the place of the one 
that has been in service for a week. A single 
spare unit in an installation of a large number 
of units does not add a very large percentage to 
the original investment, but a spare unit to a 
single outfit nearly doubles the cost. The fol¬ 
lowing timely suggestions regarding gas engine 
practice are presented by the Gas Power Sec¬ 
tion of the A. S. M. E.: 

“Engine efficiency should be expressed in 
terms of effective heat value, until a combined 
gas-vapor cycle comes into use. For the pres¬ 
ent, let us not confound a definite engine effi¬ 
ciency by introducing the indefinite factor of 
latent heat of water vapor. Engine efficiencies 
should be given for full, to half load at least. 

“Producer Capacity. The producer should 
be rated upon its ability to gasify coal. It 
would be more accurate to rate on B. t. u. of 
standard gas, but this is impracticable. Should 
the builder desire to rate on a special coal, he 
might insert a clause limiting some of the con¬ 
stituents. In specifying sizes, a maximum as 
well as a minimum screen should be mentioned. 
A mixture of many sizes packs the producer as 
badly as a very small fuel. As a usual thing, 
the flexibility of the producer will more than 
meet the overload possibilities of the engine. 

“Producer efficiency can only be specified in 
terms of B. t. u. output, involving volumetric 
measurement, which it is usually impossible to 


118 GAS AND OIL ENGINE HAND-BOOK 


determine except by calibration of the engine. 
As we are dependent upon the engine as a gas 
meter, we must be consistent, and determine the 
efficiency of the producer in like terms; that is, 
the ratio between heat output in standard gas 
and heat input in fuel for the fire. 

“Producer Regulation. An important point 
is the property of the producer as regards the 
regulation of heat value of the gas, and its 
pressure as delivered to the engine. Quality 
regulation is covered by the engine-capacity 
clause ‘with gas of not less than so many B. t. u. 
heat value per cubic foot.’ 

“Hydrogen Content. This may be expressed 
as a percentage by volume of the gas, a per¬ 
centage by volume of combustible in the gas, a 
percentage of the heat value of the gas per 
mixture, or a percentage by volume of the mix¬ 
ture. The last appears to be the most explana¬ 
tory. The first conveys no impression of the 
commercial value of the gas. The second is 
better in this respect. The third presents widely 
varying values.” 

Gasoline Pump, A combined gasoline pump 
and gravity gasoline feed is shown in Figure 24 
The gasoline is pumped into the cup to the right 
of the pump and is from this point drawn into the 
inlet-pipe of the engine by the inductive or suc¬ 
tion action of the piston of the engine. The 
supply of gasoline to the engine is regulated by 
means of a needle-valve, the surplus gasoline fed 
to the cup is carried back to the supply tank 


GAS AND OIL ENGINE HAND-BOOK 119 


through the pipe in the center of the cup. By 
this method a constant level is maintained in the 

cup, thus ensur¬ 
ing a uniform 
supply of gaso¬ 
line to the engine 
at all times. 

Gasoline Trac- 
t i o n Engines. 
From the result 
of experience it 
has been found 
that gasoline 
traction engines 
require a double 
cylinder con¬ 
struction, as the 
duty of the en¬ 
gine is to not 
only drive the 
traction gearing 
but to propel 
itself over the roads. It is found that for success¬ 
ful work in the field, which has heretofore been 
occupied by the steam traction engine, a gas¬ 
oline engine of from 30 to 40 brake horsepower 
must be used. In an engine producing this 
amount of power in a single cylinder, the sudden 
impulses at intermittent intervals would require 
for successful operation a train of gearing so 



FIG. 24 

Combined gasoline pump and gravity 
gasoline feed to engine. 

































120 GAS AND OIL ENGINE HAND-BOOK 

large and heavy that it absolutely precludes the 
possibility of making any reasonable construction. 
When, however, the engine develops the same 
power in two cylinders with impulses twice as 
frequent and only one-half as strong, it is possible 
to make a train of gears which will transmit the 
full power of the engine and consequently a 
strong and successful gasoline traction engine. 
The builders of gasoline traction engines have 
heretofore used engines of the old models, and 
while these engines have served their purpose in 
stationary work and to some extent in portable 
work, their use has not been as satisfactory as 
with the two-cylinder style of gasoline traction 
engine. 

Gas or Oil Engines, Successful Operation of. 

Gas or oil engines are dependent for successful 
operation on two things: First, a charge of gas 
or vapor, mixed with sufficient air to produce an 
explosive mixture, and second, a method of firing 
the charge after it has been taken into the com¬ 
bustion chamber of the motor. 

When coal or natural gas is used the supply is 
taken from the main and mixed directly with the 
necessary proportion of air. When gasoline or 
kerosene is used, air is mixed with them in the 
correct proportion by carbureting devices. 

The principal parts of a gas or oil engine are 
the cylinder, the piston, the piston-rings which 
fit into grooves in the piston: two sets of valves, 


GAS AND OIL ENGINE HAND-BOOK 121 


one to admit the charge and the other to permit 
it to escape alter the explosion, a crank shaft and 
connecting-rod which connect it with the piston, 
and a flywheel, whose presence insures steady 
running of the motor, and whose further func¬ 
tions will be better understood as the descrip¬ 
tion proceeds. In the two-cycle form of gas or 
oil engine there is really but one valve, which is 
located in the crank case, the exhaust and admis¬ 
sion-ports being covered and uncovered by the 
piston itself. 

Generator. This term is usually applied to 
any form of chemical or mechanical energy which 
can be used to produce a current of electricity. 
Mechanical generators of electricity used for 
ignition purposes are of two forms, dynamos or 
magnetos. The former is self-exciting by means 
of coils of wire wound upon the magnet limbs. 
The latter has permanent magnets instead of 
coils of wire to induce the current in the arma¬ 
ture of the magneto. Magnetos, on account of 
their simplicity of construction and low first cost, 
are more generally used for ignition purposes 
than dynamos. They may be operated by the 
engine with a friction-pulley, gear or belt. 

Governing Gas or Oil Engines. There are 
various methods of governing, which are here 
enumerated and described. 

Hit-or-miss principle: Shutting off the gas or 
oil supply, opening or closing the exhaust; shut- 


122 GAS AND OIL ENGINE HAND-BOOK 


ting off the ignition, disengaging the valve 
operator. 

Throttling method: Throttling the gas or oil 
supply, throttling the charge of explosive mix¬ 
ture. 

Varying the point of ignition: In cases where 
gas or oil engines are fitted with some form of 
electrical ignition, they are sometimes regulated 
by the governor being connected with a commu¬ 
tator, which automatically cuts the current of! 
from the sparking device when the limit of speed 
has been passed, and the charge is not exploded 
till the revolutions of the engine are reduced to 
the proper speed, when the action of the governor 
closes the electrical circuit and the ignition again 
takes place. 

A similar result may be attained also by vary¬ 
ing the point of ignition, but both of these 
methods are not very economical. 

Figure 25 shows a form of governor which 
operates by preventing the exhaust-valve from 
opening. When the speed of the engine passes 
its normal limit, the balls A of the governor 
move out towards the periphery of the gear or 
wheel which carries them, causing the cam B to 
be moved. to the right by the action of the dogs 
on the governor arms, which engage in a grooved 
collar on the sleeve C. 

The nose of the cam B is thus kept out of 
engagement with the roller D until the motor 


GAS AND OIL ENGINE HAND-BOOK 123 


resumes its normal speed, thus preventing the 
valve-lifter from opening the valve. 

Normally the cam is held in position by the 
springs attached to the governor balls, against 



FIG. 25 

Exhaust-valve governor which operates by throwing the cam out 
of contact with the cam-roller. 


the shoulder of the bearing F, which carries the 
cam-shaft G. 

A form of governor is shown in Figure 26 
which may be used in connection with any of the 
methods of governing described above. It is 


































124 GAS AND OIL ENGINE HAND-BOOK 

usually located on an independent bracket and 
driven from the cam-shaft of the motor. 

Figure 27 shows a governor working on the 
hit-and-miss principle. When the engine tends to 
run above its 
normal speed, 
the action of the 
governor balls 
causes knife- 
edge to move 
away from the 
notch in the end 
of the valve 
plunger, thus 
throwing the 
valve out of ac¬ 
tion. 

An inertia 
governor is 
shown in Figure 
28 Should the 
engine attempt 
to increase its 
speed above nor¬ 
mal, the lower 
end of the double-ended lever, at the left 
in the drawing, will be depressed by the cam 
and the valve-lifter thrown out of an engage¬ 
ment with the step immediately above the roller, 
in this manner preventing any further action of 



FIG. 26 

Centrifugal governor for operating either 
hit-and-miss or throttling forms of 
speed regulating mechanism. 


















GAS AND OIL ENGINE HAND-BOOK 125 


the valve-lifter until the speed of the motor is 
reduced. 

Hand Starting Device. A hand starting 
device, for starting engines of from 10 to 25 
horsepower, is shown in Figure 29, the flywheels 
of the engine are turned over until the piston is 
just past the dead center of the explosion or 
power stroke, the combustion chamber is filled 
with an explosive mixture by means of a hand 



FIG. 27 

Hit-and-miss type of centrifugal governor which operates by 
throwing the knife-edge out of contact with the 
valve-stem lifter- 


pump, after a match has been inserted in the cock 
shown to the left in the drawing. The plug of 
the cock is closed, cutting off the match, the 
plunger is given a smart blow with the hand, the 
match is then consequently fired, the charge 
ignited and the piston started on its working or 
power stroke. 















126 GAS AND OIL ENGINE HAND-BOOK 


Hornsby-Akroyd Oil Engine. In this en¬ 
gine, a sectional view of which is shown in 
Figure 27 a, the oil is first introduced in liquid 
form into the vaporizer shown at the back of 
the cylinder. The heat necessary for vaporiz¬ 
ing the oil is supplied at starting by external 



FIG. 27a 

Hornsby-Akroyd horizontal engine 


lamps, but when the engine is in operation the 
continued combustion of the fuel supplies suffi¬ 
cient heat for both vaporization and ignition. 
Air necessary for combustion is introduced into 
the cylinder during the suction period of the 
cycle, this being a four-cycle engine. Thus the 
cylinder becomes charged with air and the vapor¬ 
izer becomes filled with a spray of oil, both events 
occurring simultaneously. During the compres¬ 
sion period the air in the cylinder being forced 
































GAS AND OIL ENGINE HAND-BOOK 127 



FIG. 27b 

Hornsby-Akroyd vertical engine 



































































128 GAS AND OIL ENGINE HAND-BOOK 


into the vaporizer becomes properly mixed with 
the oil and an explosive mixture is formed. The 
deposit of carbon frequently found where crude 
oil is used does not enter the cylinder nor come 
in contact with the piston or piston rings, but is 
formed in the vaporizer cap. A flange cover at 
the back of the cap allows the quick removal 
of this deposit periodically, usually about every 
sixty hours of running. In the vertical type of 
the Hornsby-Akroyd engine, shown in section 
in Figure 27 b, the vaporizer is placed horizon¬ 
tally on the side of the cylinder, while the air and 
exhaust valves are located in housings in the top 
cover. As is the case with the horizontal type 
shown in Figure 27 a> the ignition of the gases 
in the cylinder is caused automatically by the 
heat of compression,, together with the heat 
stored in the walls of the vaporizer. The method 
of governing consists in the automatic lengthen¬ 
ing and shortening of the stroke of the oil supply 
pumps, thus giving very close regulation. 

Horsepower of Gas or Oil Engines. A horse¬ 
power is the rate of work or energy expended in 
raising a weight of 550 pounds one foot in one 
second, or raising 33,000 pounds one foot in one 
minute. A good horse for a short period of time 
can do much more. 

As the ordinary formula used for the calcula¬ 
tion of horsepower in connection with steam 
engines is not directly applicable to gas or oil 


GAS AND OIL ENGINE HAND-BOOK 129 

engine practice, formulas are here given that are 
more suited to the purpose. 

Let D be the diameter of the cylinder in inches, 
and S the stroke of the piston also in inches: if 



F!G. 28 

Inertia type of governor, which operates by throwing the 
valve-lifter rod out of contact with the cam-roller lever 

N be the number of revolutions per minute of the 
motor, and H.P the required horsepower of the 
motor, then for a four-cycle motor 

hp _ d 2 xsxn 


18,000 



















130 gas and oil-engine hand-book 


Example: What horsepower should be devel¬ 
oped by an engine of 4j inches bore and 6 inches 
stroke, at a speed of 600 revolutions per minute? 
Answer: The square of the bore multiplied 

by the stroke is 
equal to 121.5, 
this multiplied 
by 600, and di¬ 
vided by 18,000, 
gives 4.05 as 
the horsepower 
of the motor. 

From a theo¬ 
retical stand¬ 
point a two- 
cycle engine 
should not only 
have as great a 
speed but also be 
capable of de- 

FI G. 29 veloping almost 

Match igniter for starUng gas or gasoline twice ^ power 

that a four-cycle 
engine does. It is a fact, nevertheless, that its 
actual performance is far different. 

The horsepower of a two-cycle engine may be 
calculated from the following formula: 

,t p _ D 2 X S X N 
21,000 

Example: Required, the horsepower of a 

















GAS AND OIL ENGINE HAND-BOOK 131 


two-cycle motor of 4j inches bore and 6 inches 
stroke, with a speed of 600 revolutions per minute? 

Answer: The square of the bore multiplied 
by the stroke is equal to 121.5, which multiplied 
by 600, and divided by 21,000, gives 3.47 as the 
required horsepower. The results given by the 
above examples agree very closely with those 
obtained from actual practice. 

Indicated horsepower is the actual power pro¬ 
duced in the cylinder, from which must be 
deducted the power required for driving the 
engine itself. 

Brake horsepower, also called actual horse¬ 
power, is the net effective power given off at 
the driving pulley of the engine, and this form of 
horsepower is the one for which a guarantee 
should be obtained from manufacturers by users. 

Hot Tube Ignition. The incandescent tube 
system of ignition consists of a tube of metal or 
porcelain, one end of which is closed and the 
other screwed or fastened into the combustion 
chamber by suitable means. 

The flame of a Bunsen burner is projected 
against the ignition tube, rendering it incandescent, 
resulting in the firing of the compressed charge 
slightly before the end of the compression stroke. 

The Bunsen burner should be adjusted so as 
to give a small blue flame entirely round the 
ignition tube. If too much gas is being used, a 
smell will come from the chimney. 


1132 GAS AND OIL ENGINE HAND-BOOK 

It is important that the ignition tube be always 
kept to a bright red heat, should it be allowed to 
get foul, misfires will occur. 

Ignition tubes should be renewed as soon as 
they begin to appear defective, which will be 
indicated by irregularity in the firing, as, 
although the engine may continue working for 
some time, a considerable loss of gas may be 
going on. 

In putting in a new ignition tube care should 
be taken that no grit is allowed to get into the 
passage leading to the combustion chamber. 

Igniter, Cleaning an. The igniter should be 
taken off and cleaned after intervals of from sixty 
to ninety days of constant running. All carbon 
and corrosion should be removed from the igniter 
points and mica washers. 

Ignition, Catalytic. This method of ignition 
for gas or oil engines is based on the property 
possessed by spongy platinum of becoming incan¬ 
descent when in contact with coal gas or car¬ 
bureted air. With this means of ignition, speed 
regulation or variation can only be had within 
very narrow limits. The principal objections to 
its extended use are, danger of premature ignition, 
lack of speed control and difficulty of starting the 
motor. 

Ignition, Forms of. The earlier forms of gas 
engines built had the compressed charge ignited 
by means of a flame, which has, however, now 


GAS AND OIL ENGINE HAND-BOOK 133 


given place to the three following methods of 
ignition: 

Hot surface. 

Hot tube. 

Electric. 

The first-named form of ignition is illustrated 
in Figure 42. In this form the heated walls 
of the vaporizer act as the igniter, aided by the 
heat generated during the compression of the 
gases. The chamber being first heated, after¬ 
ward the proper temperature is maintained by 
the heat caused by the combustion of the gases. 
Various other devices in which heat is maintained 
to cause self or spontaneous ignition are now 
made. 

The second type, that of the hot tube, is 
shewn in Figure 19 at P. This form of ignition 
consists of a metal tube fitted into the vapor¬ 
izer or cylinder wall. It is closed at one end, 
the other end being open to the cylinder. It 
is heated by a Bunsen flame over part of its 
length. When compression due to the inward 
stroke of the piston takes place in the cylinder 
the explosive mixture is compressed into the tube 
and is ignited by coming in contact with the 
heated portion of it. Nickel-steel tubes are 
preferable to wrought iron, although both are 
used for this purpose. 

The third form, that of electric ignition, is of 
two kinds, the primary make and break., with 


134 GAS AND OIL ENGINE HAND-BOOK 


which a mechanical device to make the primary 
circuit in the combustion chamber of the motor is 
used, and the secondary or jump-spark form of 
ignition, in which the spark jumps or arcs within 
the cylinder without the aid of any mechanical 
device. 

Ignition Mechanism. A form of ignition 
mechanism used in connection with the primary 
make and break system of electrical ignition is 

i 11 u s t r a ted in 
Figure 30. Up¬ 
on the operating 
rod being moved 
to the left, the 
pawl carried by 
the upper arm 
of the bell-crank 
lever forces 
downward the 
FIG. 30 small trigger 

Ignition mechanism for use in connection ; j 

with a primary make and break spark. carried upon ujg 

outer end of the 

movable electrode and in this manner passes 
by it. Upon the return stroke of the operating 
rod the upper end of the pawl engages with the 
trigger, bringing the contact-points of the movable 
and fixed electrode together for a short period of 
time. A further movement of the operating iod 
in the same direction causes the trigger to be 
released from contact with the pawl. This 








GAS AND OIL ENGINE HAND-BOOK 135 


action causes the contact-points of the electrodes 
to suddenly fly apart and a spark or arc is pro¬ 
duced between them. 

The make-and-break system is used princi¬ 
pally in stationary and portable gasoline en¬ 
gines of medium or slow speed, where the mov¬ 
able terminal with a stationary are located with¬ 
in the ignition chamber, and by actuation from 
outside mechanism the movable igniter point 
makes regular successive contacts and separa¬ 
tions with the stationary terminal, thus serving 
as both igniter point or terminal and circuit 
breaker. It also uses a simple primary spark 
coil. 

The jump spark system is used principally 
on automobiles and other high speed gasoline 
motors, and carries its current through an in¬ 
duction coil to a jump spark plug screwed into 
the cylinder with both terminals stationary and 
standing apart with only a slight gap between 
and with a circuit breaker attached to some 
other part of the engine mechanism. 

The primary coil is not commonly known as 
an induction coil, although it is referred to as 
having self-induction. 

While the jump spark coil serves its purpose 
by inducing a current in its secondary coil, the 
primary, or make-and-break coil, has only a 
single coil of wire around a soft iron core. 

The jump spark, or induction coil, has always 
two separate and distinct coils. The one next 
to the soft iron core is called the primary and 


•136 • GAS AND OIL ENGINE HAND-BOOK 


the one wound around the primary, though not 
connected with it but insulated from it is the 
secondary coil. 

Testing the Coil. If a coil fails to work, the 
trouble may be in wiring from coil to battery. 
Test by carrying wires direct from coil to bat¬ 
teries; then if it works right, the fault must 
have been either in the wiring or commutator 
(timer), but if it still fails to work, examine 
the platinum points for dirt or pitting; in this 
case remove vibrator and file the points flat and 
even with a fine file; do not have the hammer 
spring too, stiff. Adjust the contact screw so 
that the platinums have a space between them 
of about the thickness of an ordinary card. 

If vibrator operates but does not produce a 
spark, if there is much spark at the platinums, 
it is an indication that the condenser in the 
coil is poorly or wrongly connected or one of 
the platinum points is gone; in either case there 
will be a weak spark. If the vibrator works 
and there is no spark there must be a short- 
circuit or break in the secondary of the coil. 
If there is battery current up to the coil ter¬ 
minals and vibrator does not work, there is a 
break in the primary coil or dirt on platinum. 
If a spark is produced at battery terminals of 
the coil, but no vibrating, and the spark com 
tinues when the top contact screw is removed* 
there is a short circuit in the primary winding. 
Defects in the secondary and primary windings 
should be corrected by the manufacturer of the 
coil. 


GAS AND OIL ENGINE HAND-BOOK 137 


When a good spark is obtained at the end of 
secondary wire and none or a poor spark at the 
plug, the point or points need adjusting or the 
spark plug is short-circuited. 

The mission of the coil is to transform the 
low pressure electricity in the batteries to high 
tension current. 

If the coil is in good condition it is easily ad¬ 
justed by experimenting with the set screws. 
Contact points are often ruined by too stiff an 
adjustment or by too many batteries. Have the 
least tension possible with good results. 

A spark that shows fat and strong in the open 
air may be found too weak when exposed to the 
pressure of several atmospheres in a gas engine 
cylinder. A spark strong enough to jump an 
eighth of an inch may be able to jump only 
half that far under pressure. Spark plug points 
should be about one-thirty-second of an inch 
apart and must be kept clean to give good serv¬ 
ice. 

To test a plug for short-circuiting or other 
trouble, unscrew it from cylinder and lay it on 
the cylinder head wired as before. With switch 
on, turn engine over to firing point and note if 
you have a good spark. Remember that under 
these conditions the spark must be large and 
hot, for it will not be so strong in the cylinder, 
where the pressure is much greater. 

The timer works in conjunction with the plug 
and coil, and causes the spark to occur at the 
right moment. The contact points in the timer 


138 GAS AND OIL ENGINE HAND-BOOK 

must be kept clean, and the box packed with 
good grease. 

Wiring often causes trouble due to the use of 
an inferior quality or the wrong kind. Always 
use the best wire; it does not cost much more 
than the cheap kind and is far less expensive in 
the end. The secondary wire should always be 
large, for it offers much less resistance. This 
does not apply to the insulation, and you must 
not judge the wire by the size of the insulation. 
That, of course, is necessary, but the copper is 
what counts. Never use lamp cord, electric light 
or telephone wires under any condition. The 
ends of all wires should be protected by copper 
terminal connections. These are inexpensive, 
and insure a positive connection besides present¬ 
ing a very neat effect. 

It is important to use large wire for the pri¬ 
mary circuit, but not as large as that used for 
the secondary. 

Testmg Batteries. Weak batteries cause more 
trouble in the gas engine than any other factor. 
There is but one remedy. If storage batteries 
are used, they will have to be recharged, and if 
dry cells, they will have to be replaced by new 
ones. 

Possibly all dry cells may not be low; this 
can readily be ascertained by testing the cells 
separately. If they show less than eight am¬ 
peres, they should be replaced. New cells should 
show about one and a half volts and twenty 
amperes each at least. Be sure always to have 


GAS AND OIL ENGINE HAND-BOOK 139 


the cell nearest the coil strong, for if this one is 
weak it will exhaust the others. 

Storage cells should always be tested with a 
voltmeter, and each should develop about two 
volts. If less, they should be recharged. A 6- 
volt 60-ampere storage battery is generally the 
best size to use with the jump spark system. 

Remember to adjust the coil immediately after 
connecting new batteries; for if this is not done 
there is danger of burning contact points, due 
to the vibrator screw being set too fine. This 
needed adjustment is easily explained; when the 
batteries become weak it is necessary to tighten 
up the contact screws on coils. 

Do not make the common mistake of using 
batteries according to their voltage strength 
when not in service. 

Ignition Dynamo. Batteries have not 
proven entirely satisfactory with either high or 
low-tension ignition systems, tlie current being 
subject to a gradual weakening as the batteries 
become exhausted. 

This led to the development of the ignition 
dynamo, which is simply a machine for convert¬ 
ing mechanical into electrical energy, and con¬ 
sists of some insulated wire wound on a shaft¬ 
like member called an armature, which is rotated 
in a magnetic field, this movement producing an 
electric current in the wire which, according to 
the construction of the machine, may be either 
of the high or low-tension variety. 

A typical low-tension dynamo is shown in Fig- 


140 GAS AND OIL ENGINE HAND-BOOK 

ure 31. The pole pieces A and B are made from 
soft iron and are wound with field coils consist¬ 
ing of many turns of wire, as indicated at C 
and D. This winding is connected in series with 
the winding F of the armature by means of the 



Illustrating basic principles of the dynamo. 

upper brush G and the segments EE of the 
commutator. 

The armature core on which the winding F, 
consisting of many turns of wire, is wound is 
not shown for the sake of clearness, but it will 
be understood that it, together with the wire, 



























GAS AND OIL ENGINE HAND-BOOK. 141 


revolves in a space between the pole pieces, com¬ 
monly known as the field, and when the arma¬ 
ture is turned at a fair rate of speed a current 
of electricity will be produced, which is led to 
the ordinary make-and-break igniter by means 
of the wires shown on the right of the cut. 

It is necessary that the armature be rotating 
rapidly before sufficient current will be produced 
to flow through the coils C and D to magnetize 
the pole pieces and produce a field for the arma¬ 
ture, so the machine can generate a current suf¬ 
ficiently strong for ignition purposes; therefore 
this type of machine must run at least 300 
r. p. m., and it is sometimes difficult to attain 
this when starting the engine. From 1,000 to 
1,500 r. p. m. is the average running speed neces¬ 
sary to give the best results. 

As the machine must build up, as it were, 
the length of time during which the igniter 
points are closed together is of considerable im¬ 
portance, for during this period the current 
flows in the circuit and builds up the magnetism 
of the pole pieces, thereby increasing the 
strength of the current generated. When the 
igniter points separate, the flow of stored-up 
energy is suddenly interrupted, and this energy 
dissipates itself in the form of a spark. 

This type of machine is usually driven by a 
small friction wheel adapted to bear against the 
face or side of the engine flywheel. A governor 
is interposed between the friction wheel and the 
dynamo, so that when the speed is excessive the 


142 GAS AND OIL ENGINE HAND-BOOK 


friction wheel will be drawn away from the fly¬ 
wheel and the speed decreased. It is also possi¬ 
ble to use a belt, or multiplying gears. The 
most common method, however, is the friction- 
driven. 

As most engines are hard to turn over by 
hand, and can only be turned over slowly, it is 
obvious that with dynamos of this type it would 
be very hard to start the engine, so the dynamo, 
a set of batteries and coil are connected up as 
shown in Figure 32, and the engine started on 



Showing connections for ignition, dynamo, battery and spark 
coil. 


the batteries, and then, after it is started, 
switched to the dynamo. Of course, this makes 
the dynamo dependent on the battery, and in 
case the battery should fail the engine could not 
be started to put the dynamo to work. This 
method, however, will be found of great advan¬ 
tage in starting, as it saves a lot of work in 
turning the engine, and provides two sources of 
current supply—the batteries being ready in case 
the dynamo should fail. 
















GAS AND OIL ENGINE HAND-BOOK 143 


Care must be taken when using a dynamo of 
this type to see that it is properly connected to 
the engine, and that an efficient governor is 
used. 

Magnetos. The fields of a magneto are made 
of permanent magnets. Those of the dynamo 
described are electro magnets. This, then, is the 
essential difference between these two types of 
generators. The dynamo is provided with a 
field winding; that is, a coil of wire which sur¬ 
rounds the field pieces and either all or a part of 



FIG. 33 

Magneto armature. 


the current generated flows through this wind¬ 
ing. This is what generates the magnetic field 
between the pole pieces. In the magneto there 
is no winding around the field pieces. These, 
instead of being made of soft iron, are made of 
hardened steel and permanently magnetized. 
The armature is also made differently. It con¬ 
sists of an H-shaped piece of soft iron, around 
which a single continuous coil of wire is wound 
parallel with the axis. Figure 33 shows the 




144 GAS AND OIL ENGINE HAND-BOOK 


simplest style of magneto armature, and Figure 
34 shows an end view of the complete machine 
assembled. 

The armature fits very closely between the 
pole pieces, having a clearance of only about 
one one-hundredth of an inch. The pole pieces 
P (Figure 36) are made of soft iron and the 
lines of force pass from the positive pole to the 



negative through the soft iron H of the arma¬ 
ture. The manner in which the current is gen¬ 
erated will now be described. 

When the armature is in the position shown 
in Figure 34 the lines of force pass from one 
pole piece to the other through the soft iron 
neck of the armature, since that is the only path 
they can travel. The brass plate at the bottom 












GAS AND OIL ENGINE HAND-BOOK 145 


is not a conductor of magnetism and no lines of 
magnetism can pass from one pole to the other 
through it. The armature acts just like the 
keeper or flat piece of iron that is laid across the 
ends of a horseshoe magnet. When the arma¬ 
ture is not in position the lines of force will 



pass through the air along the lines of least 
resistance, through a-a or b-b. But the greater 
number will pass between the points b-b, since 
these are the nearest together. When the arma¬ 
ture is in the position shown in Figure 34, all 
of them will pass through the neck of the arma¬ 
ture, as before stated. 

When the armature is turned to the position 
shown in Figure 35, the lines of force are dis¬ 
torted, as shown, but still flow through the neck 
N. But when the armature is turned still far- 









146 GAS AND OIL ENGINE HAND-BOOK 


ther, so that N stands vertical, as in Figure 36, 
the lines of force no longer flow through N, but 
take two paths, one across a-a , the other b-b, 
sin^e these are the paths of least resistance. 



FIG. 36 


When the lines of force are flowing through 
the neck N, as in Figure 34, the soft iron core 
is strongly magnetized, but when the armature 
revolves to the position of Figure 36, N is de¬ 
magnetized. In this way the magnetism of the 
armature varies from a maximum, when the 
neck N is horizontal, to almost nothing when it 
i* vertical. 

While the strength of the current is in some 
respects dependent on the speed of this machine, 
it is not nearly so much so as with the wire 
wound type of Figure 31, as the strength of the 
permanent magnets is always at its maximum 













GAS AND OIL ENGINE HAND-BOOK 147 

and the speed of the armature does not affect 
it; therefore, at a comparatively low speed the 
magneto will give its maximum current. 

As the strength of the magnets does not in¬ 
crease with the speed, it is impossible to gen¬ 
erate sufficient current to burn out the machine. 
The commutator and brushes are also necessary, 
and the result is a machine of the simplest possi¬ 
ble construction. 

Current of this description is called alternat¬ 
ing, and Figure 37 illustrates the wave of cur¬ 
rent of this kind produced by one complete revo¬ 
lution of the armature. On the left, for the 
sake of illustration, are figures representing the 



current strength or voltage, while the points 1 
and 2 along the curved lines represent the posi¬ 
tions of the armature shown in Figures 34 and 
36. Starting at the heavy horizontal lines, 
where there is no current, the upper heavy 
curved line represents one-half of the revolution 
of the armature, and the curved line below the 
horizontal line, the other half revolution. 

From this it will be seen that the current flows 
first in one direction and then the other, the 












148 GAS AND OIL ENGINE HAND-BOOK 


strength increasing from O to 1, then decreas¬ 
ing to 2, as the wire at this point is no longer 
subject to the lines of force. The current then 
increases to 3, in the opposite, and again de¬ 
creases to O. 

From a study of this figure it will be seen 
that the current is strongest when the armature 
is in a certain position; this point is called the 
peak of the current, and there are two peaks 
for each revolution of the armature. The mag¬ 
neto must be so timed in relation to the spark¬ 
ing moment of the engine that the igniter will 
operate to produce the spark at the same instant 
the armature is at the peak; this is termed 
timing the magneto, and it is very important 
that this be accurately accomplished. This 
timing necessitates some positive mechanical 
means of driving the magneto, and will not per¬ 
mit the use of belts or friction pulleys, or any 
intermediate device, such as a governor, for it is 
evident that anything liable to throw the mag¬ 
neto out of time with the engine would result 
in the igniter points being separated when the 
armature is in an intermediate position—say, 
midway between O and the peak, and it is obvi¬ 
ous that the current strength is not at its maxi¬ 
mum and the spark would be too weak. 

A well-designed and properly-constructed 
magneto should last as long as the engine, if the 
alternating current type without field coils, com¬ 
mutator or brushes is used, as this is a very sim¬ 
ple machine, and when equipped with ball bear¬ 
ings there is practically nothing to wear. 


GAS AND OIL ENGINE HAND-BOOK 149 


In testing the alternating current magneto, 
disconnect all wires, and place the fingers— 
slightly moistened—on the terminals of the mag¬ 
neto to which the wires connect. A smart shock 
should be felt, and if this is the case the mag¬ 
neto is O. K. 

While running, a piece of wire can be con¬ 
nected to one terminal, and then quickly tapped 
on the other, and if this is done at the right in¬ 
stant (when the magneto is at the peak) a bright 
spark should be produced. 



Ignition by Compression . In the Diesel oil 
engine a charge of air is drawn into the cylinder 
on the aspirating or charging stroke, but no 
fuel. This air is compressed to a very high 
pressure, usually above five hundred pounds per 
square inch. When air is compressed so strongly 
the work done upon it is transformed into heat 
and its temperature rises very high. If now 
when the piston reaches the end of its stroke a 
jet of oil is pumped in, this oil will be ignited 




















150 GAS AND OIL ENGINE HAND-BOOK 


by the hot air and no other form of igniter 
will be needed. A governor attached to the 
pump regulates the time during the power stroke 
that the oil jet is admitted, which generally does 
not exceed one-tenth of the stroke. 

Figure 38 shows the method of igniting the 
charge in the Hornsby-Akroyd oil engine. The 
chamber at the left of the cylinder is not water 
jacketed. It is first heated by an auxiliary 
burner to a red heat. Then when the piston 
makes its first outward stroke the air is drawn 
into the cylinder and a thin jet of kerosene is 
forced into the hot chamber and is instantly 
vaporized. On the compression stroke the air 
is forced back through the narrow neck into the 
vaporizing chamber, where it mixes with the 
fuel. Ignition is caused by the heating effects 
of compression, friction and the heat of the 
vaporizer. At first thought it might be sup¬ 
posed that when the oil first enters the vaporizer 
it would be ignited, but this cannot occur, be¬ 
cause it has no air to combine with. The air 
that is entering the cylinder during the charg¬ 
ing stroke is moving toward the rear of the 
cylinder away from the fuel. On the compres¬ 
sion stroke this air is forced into the chamber 
with the fuel, and when the compression stroke 
is nearly completed the air has mixed with the 
vaporized fuel sufficiently to cause an explosive 
mixture and ignition takes place. A governor 
controls the stroke of the pump and allows the 
correct amount of oil to be delivered to maintain 
the speed of the engine. 


GAS AND OIL ENGINE HAND-BOOK 151 

There are no means for changing the time of 
ignition. This engine is adapted for using kero¬ 
sene or heavier oils. 

Ignition, Reason for Advancing Point of. 

It may be well to explain, without entering into 
theoretical details, that when an engine is running 
at normal speed the ignition mechanism is so set 
that ignition takes place slightly before the piston 
reaches the end of its compression stroke. 

If the charge is fired at or after the end of the 
compression stroke, the average pressure on the 
piston, and consequently the power, is decreased 
in proportion. Therefore to ensure perfect com¬ 
bustion with a maximum pressure at the com¬ 
mencement of the explosion stroke, the point of 
ignition must be earlier, and advance as the 
speed increases. 

Indicator Diagrams. The thermal or heat 
efficiency of a gas or oil engine may be deter¬ 
mined from an indicator diagram, which gives a 
representation of the internal conditions through¬ 
out the entire cycle of operations. The diagram 
tells many things essential to be known. 

It gives the initial explosive pressure, or the 
pressure a moment after ignition has taken place. 
It shows whether the volume of the charge is 
diminished during the period of admission. It 
gives the point of ignition, when the ignition is 
complete and when expansion begins. It indi¬ 
cates the pressure of expansion during the work- 


152 GAS AND OIL ENGINE HAND-BOOK 

mg stroke. It gives the terminal pressure when 
the exhaust is opened. It shows the rapidity of 
the exhaust. It indicates the back-pressure on 
the piston, due to the exhaust. It shows the 
point of opening of the exhaust. It gives the 
mean power used in driving the motor. It also 
indicates any leakage of valves or piston. 

The usual method of ascertaining the area of 
an indicator diagram is by means of an instru¬ 
ment known as a planimeter, which is used to 
calculate the area of any irregular surface, by 
moving a tracing point attached to the instru¬ 
ment over the entire irregular boundary line of 
the figure. 

But for the purpose of ascertaining the horse¬ 
power of an engine it will be sufficiently accurate 
to illustrate the principles involved, to calculate 
the area of the diagram by means of ordinates or 
vertical measurements. 

The upper drawing in Figure 88a represents 
a card taken from an engine of 4 inches bore and 
6 inches stroke, at 600 revolutions per minute, 
and under a full load. The diagram is divided 
into 12 parts as shown by vertical lines, the 
lengths of which are in terms of the spring, 
which is 100. Then 1.90+1.36+1.00, etc., 
divided by 12, equals 0.665 as the average height 
of the diagram. Its length is 6 inches, as shown, 
therefore the area of the card is approximately 
3.99 square inches. As the initial explosive force 


GAS AND OIL ENGINE HAND-BOOK 153 


from the diagram is 250 pounds per square inch, 
and a 100 indicator spring used, the height of 
the card is 250 divided by 100, which equals 
2-J- inches as the height of the card. The mean 
effective pressure on the piston in pounds per 



square inch will therefore be equal to the area of 
the diagram 3.99, divided by the area of the 
whole card, which is 2|X6, equals 15, and multi¬ 
plied by 250, the initial explosive force, or 
3.99X250, and divided by 15, equals 66.5 pounds 









154 GAS AND OIL ENGINE HAND-BOOK 


per square inch as the mean effective pressure 
required. 

From this the indicated horsepower of the 
engine can readily be found as follows: 

Let M.P be the mean effective pressure in 
pounds per square inch, A the area of the cylin¬ 
der in square inches, S the stroke of the piston in 
inches, N the number of explosions per minute, 
and H.P the indicated horsepower, then 

_ M.P X A X S X N 
H * P - 396,000 

_ 66.5 X 12.56 X 6 X 300 _ o 
” 396,000 ' 

as the required indicated horsepower of the 
engine. The indicated horsepower of any engine 
will always be greater than that obtained from a 
brake test, as it simply represents the actual 
thermo-dynamic (heat-pressure) conditions within 
the cylinder, and takes no account of friction and 
other external losses. 

The lower drawing in Figure 38a is a card 
taken from the same engine running under half 
load. 

Indicator, Use of the. An indicator consists 
of a cylinder within which works a piston under 
the tension of a helical spring of predetermined 
strength. The rod attached to the piston carries 
a pivoted arm which works on a horizontal lever. 
This lever carries a pencil bearing against a 




GAS AND OIL ENGINE HAND-BOOK 155 


drum. This drum is so arranged with a spring 
that it may be partially rotated by the pull on an 
attached string. A sheet of paper is wound on 
the drum and held in place by spring clips. The 
pressure in the cylinder acting on the spring 
causes the pencil to mark the paper, the indicator 
card or diagram being traced by the forward and 
backward movement of the drum. 

Inspecting Gas or Oil Engines. Before 
examining an engine with a light, care should be 
taken that the combustion chamber is free from 
gas mixture. This can be done by turning the 
engine round a few times. The ignition should 
be cut out and the fuel supply cock closed. It is 
more or less dangerous to look down the chimney 
of the ignition tube when the engine is running. 

It is sometimes necessary to inspect the interior 
of the engine cylinder with a lighted candle, for 
the purpose of locating some sharp projection, 
burnt carbon, crack or sand hole, etc. When 
doing this, always remember that a charge of 
fuel may remain in the cylinder, and whether the 
candle is inserted through one of the valve ports 
or the open end of the cylinder, be sure to keep 
the face away from the opening. 

Installing a Gas or Oil Engine. Secure the 
engine to a good foundation made according to 
the plans furnished by the engine builder. 

Set up the water tank at any convenient dis¬ 
tance from the engine, preferably as close as 


156 GAS AND OIL ENGINE HAND-BOOK 


possible on the exhaust side. Use short pieces 
of rubber hose in the cooling tank piping. Put 
the shut-off valve close to the tank. Be sure that 
the vent pipe is long enough to be above the top 
of the tank. Water should always be at least 
6 inches above the upper pipe or it will not 
circulate. 

The water tank may be dispensed with by 
connecting a water feed pipe direct from a 
hydrant to the opening in exhaust valve chamber 
and running a waste pipe from top of cylinder 
jacket to carry off the water. 

Regulate the amount of water by means of a 
stopcock placed in this pipe. 

Keep the cylinder jacket just as hot as can be 
borne by the hand, say from 140 to 160 degrees 
Fahrenheit. 

The fuel tank may be placed outside of the 
building and should be in a vertical position, 
twelve to eighteen inches lower than the top of 
the foundation, so that the fuel will flow from 
engine to tank. Care should be taken to wash 
out every piece of pipe with gasoline before con¬ 
necting up, this removes all dirt and scale which 
would interfere with the proper working of the 
check valves. Extra care should be taken in 
making all water and fuel pipe connections 
tight. Use soap in the joints of the fuel pipes. 

Run the exhaust pipe in any convenient direc¬ 
tion, placing the muffler as near the engine as 


GAS AND OIL ENGINE HAND-BOOK 157 


possible. Never use a pipe smaller than the 
opening in the muffler. Long and crooked runs 
should be avoided, but if necessary use a size 
larger pipe It is not advisable to exhaust into 
a chimney. 

Long vertical pipes collect water and should 
be connected with a Tee fitting at the bottom 
provided with suitable connections for draining. 

Connect the battery cells with the spark coil, 
switch and binding posts on the engine. The 
ends of wares where the connections are made 
should have all the insulation removed and all 
nuts tightened well to insure good connections. 

Jump-spark Wiring Diagram. A method of 
waring for a single cylinder engine using a set of 
batteries and a magneto-generator is illustrated 
in Figure 39. By moving the switch-finger, 
either the magneto-generator or the battery may 
be used as desired, or both cut out. 

Knocking or Pounding in an Engine. May 
be due to any of the following causes: 

Premature ignition: The sound produced by 
premature ignition may be described as a deep, 
heavy pound. 

Using a poor grade of lubricating oil will cause 
premature ignition. The carbon from the oil 
will deposit on the head of the piston in cakes 
and lumps, and will not only increase the com¬ 
pression but will get hot after running a short 
time and wdll ignite the charge too early, and 


158 GAS AND OIL ENGINE HAND-BOOK 



















































GAS AND OIL ENGINE HAND-BOOK 159 


thereby produce the same effect as advancing the 
spark too much. If this is the cause the pound¬ 
ing will cease as soon as the carbon deposit is 
removed from the combustion chamber. 

Badly worn or broken piston-rings. 

Improper valve seating. 

A badly worn piston. 

Piston striking some projecting point in the 
combustion chamber. 

A loose wrist-pin in the piston. 

A loose journal-box cap or lock-nut. 

A broken spoke or web in the flywheel. 

Flywheel loose on its shaft. 

If the sparking device be placed so as to be 
exactly in the center of the combustion space an 
objectionable knock occurs, which has never 
been fully explained. In some engines it renders 
a particular position of the ignition unusable, 
this form of knock disappears either on making 
a slight advance or retardation of the ignition. 

If the cylinder is in good condition, and a 
bumping noise is heard when working at full 
load, it may arise from too much oil being sup¬ 
plied to the engine, which should be regulated 
accordingly. 

Explosions occurring during the exhaust or 
admission stroke. This is almost always due to 
a previous misfire, and it may be prevented by 
stopping the misfires. 

If the ignition is so timed that the gases reach 


160 GAS AND OIL ENGINE HAND-BOOK 


their full explosion pressure during the compres¬ 
sion stroke, that is, if the spark be unduly 
advanced, an ugly knock occurs, and great pres¬ 
sure is developed on the crank-pin bearing, wrist 
pin, and connecting-rod. The effect may be the 
bending or distorting of the connecting-rod. 

The crank-pin may not be at right angles to 
the connecting-rod. This cause of knock is often 
hard to find. 

The bearings at either end of connecting-rod 
may be loose. A knock during the explosion 
stroke, and also at each reversal of the direction 
of the piston. 

If the crank shaft is not perfectly at right 
angles to the connecting-rod, the crank shaft and 
flywheels will travel sideways so as to strike the 
crank shaft bearings on one side or the other. 


GAS AND OIL ENGINE HAND-BOOK 161 


Lauson Heavy-Duty Kerosene Engine.— 

This engine is of the vertical four-cylinder type, 
designed primarily to operate on kerosene oil, 
although it may be operated on power distillate, 
or gasoline. Figure 39 a shows a vertical cross- 
section through one cylinder and the frame. The 
fuel is admitted to the cylinders by means of 
poppet inlet valves located in the cylinder heads. 
These valves, as will be seen from Figure 39 a, 
are operated by overhead tappets which receive 
their motion from a camshaft. The products of 
combustion are exhausted from the cylinders by 
means of exhaust valves also located in the cyl¬ 
inder heads and operated by the same camshaft. 

Fuel Feeding Devices .—The Lauson engine 
is equipped with a fuel feeding device, of the 
Venturi atomizer type, a sectional view of which 
is shown in Figure 39 b. The principle of this 
device is to maintain a uniformly high velocity of 
air through a Venturi tube (see D, Figure 39b), 
having radial holes in its restricted portion 
through which fuel is admitted by suction. The 
governor acts directly upon a two-ported barrel 
valve whose ports coincide with ports in the valve 
housing when the engine is at rest. See F, Fig¬ 
ure 39 b. When the engine has attained full 
speed, the barrel valve is rotated by the governor, 
thereby closing the lower port and decreasing the 
amount of fuel and air admitted into the cylinder. 
At the same time the upper port is also closed, 
deflecting more air through the nozzle and main- 


162 GAS AND OIL ENGINE HAND-BOOK 



FIG. 39a 

Cross section of Lauson heavy-duty kerosene engine 































































































































GAS AND OIL ENGINE HAND-BOOK 163 


taining practically a constant velocity of air at 
this point. Adjustment for no load and full 
load is made by means of a fuel needle valve in 
conjunction with a butterfly valve located in the 
air inlet. A separate atomizer is provided for 
each cylinder. A water feed is provided for the 


nzn 



FIG. 39b 

Venturi atomizer type fuel feeder 


purpose of preventing premature ignition when 
the engine is on full load. 

Structural Details .—The following details are 
furnished by the builders; John Lauson Co., New 
Holstein, Wis.: The crank shaft cut from the 
solid billet is carried in five bearings in the engine 
proper in addition to an outboard bearing to 
counteract the weight of the generator or belt 








164 GAS AND OIL ENGINE HAND-BOOK 


pull. The main bearings, which are removable 
without disturbing the crank case, may be ad¬ 
justed for wear, while the engine is running by 
means of bolts passing to the outside of the crank 
case as shown in Figure 39 a. 

The crank case, in which are enclosed all work¬ 
ing parts such as gears, cams, gears for driving 
the governor and magneto, is of the two-piece 
type, split horizontally at the center of the crank¬ 
shaft. 

Extra large water space and cleanout plates 
are given to the cylinders, the bore of which is 
ground after seasoning to eliminate warping. 
The heads of these cylinders, any one of which 
may be removed without disturbing any other, 
are completely water jacketed and carry the 
valves which seat directly against it, thereby 
bringing the water in close contact with the valve 
heads and avoid an undue heating of those 
members. 

The pistons used in these engines are of the 
barrel type with four rings, three on the extreme 
upper end and one on the extreme lower end, and 
are ground to accurate size. 

Forged steel connecting rods fitted with a bab¬ 
bitted steel marine type box on the lower end and 
a phosphor bronze takeup box on the upper end, 
both having exceedingly large wearing surfaces, 
are employed. 

Like the main crank, the cam shaft is carried 
in the crank case by five bronze bearings and has 


GAS AND OIL ENGINE HAND-BOOK 165 


mounted upon and keyed to it the exhaust inlet 
and igniter cams of each cylinder. The timing 
gears are also within the crank case and are held 
in position on the shaft by means of a taper fit 
and key. 

The cam shaft for operating the valves is 
carried in five bronze bearings within the crank 
case. The cams for each cylinder, viz.: exhaust, 
inlet and igniter, are integral, and keyed to the 
cam shaft. The push rods acting upon the valve 
tappets are provided with hardened sides which 
are fitted with rollers for contact with the cams. 
The tappet levers are adjustable for wear. 

Speed Regulation .—Governing is accom¬ 
plished by an enclosed vertical type of flyball gov¬ 
ernor driven from a bevel gear on the cam shaft. 
The speed of the engine may be adjusted while 
running, by shortening or lengthening the rod 
from the governor to the regulation valves. 

Ignition .—The system of ignition employed 
on the Lauson kerosene engine is of the standard 
make and break type, and is arranged with two 
timing adjustments, one individual, and one 
simultaneous. The latter adjustment is used in 
starting and is so arranged that all ignition may 
be instantly stopped by shifting the timing lever. 
Directly over the igniter is mounted an insulated 
brass bar which is charged with current from a 
gear-driven magneto. The igniters are each pro¬ 
vided with a spring coming in contact with this 
brass bar, thus eliminating wiring connections. 


166 GAS AND OIL ENGINE HAND-BOOK 


Starting .—An air starter is used which admits 
compressed air into each cylinder through an 
automatic air valve in the head. Gasoline is used 
for starting purposes until the engine is up to 
full speed, when kerosene or distillate may be 
substituted. The action of the air starter is as 
follows: It consists of a main body having four 
radial air ports connected by piping to the dif¬ 
ferent cylinders. These ports are covered, and 
uncovered by a rotary disc valve having one port. 
This disc is held to its seat by the pressure of the 
air and is free to rotate when the air is shut off. 
The starter is connected to the end of the cam 
shaft by means of a flexible coupling. To start 
the engine, all that is necessary is to turn it on 
the center and open the air cock, no shifting of 
cams and gears being required. 

Cooling System .—Water for cooling the cyl¬ 
inders and cylinder heads is circulated by a pump 
mounted directly on the engine and driven by 
means of a chain and sprocket directly from the 
crank shaft. Water is admitted to the cylinder 
on one side directly in line with the lower line of 
the compression chamber, the cooling water not 
passing directly through the lower part of the 
cylinder. This system is claimed to maintain a 
practically uniform temperature throughout the 
entire length of the cylinder. Exhaust water is 
taken out of the top of the head by means of a 
polished brass manifold. 


GAS AND OIL ENGINE HAND-BOOK 167 


Lubricants. To ensure easy running and 
reduce the element of friction to a minimum it is 
absolutely necessary that all such parts should 
be supplied with oil or lubricating grease, 
but it is also a fact, not so well understood, 
that different kinds of lubricant are necessary to 
the different parts or mechanisms of an explosive 
motor. 

As the cylinder of a gas or oil engine operates 
under a far higher temperature than is possible 
in a steam engine, consequently the oil intended 
for use in these cylinders must be of such quality 
that the point at which it will burn or carbonize 
from heat is as high as possible. 

While a number of animal and vegetable oils 
have a flashing-point, and yield a fire test suffi¬ 
ciently high to come within the above require¬ 
ments, they all contain acids or other substances 
which have a harmful effect on the metal surfaces 
it is intended to lubricate. 

The general qualities essential in a lubricating 
oil for use in gas or oil engine cylinders include a 
flashing-point of not less than 360 degrees 
Fahrenheit, and fire test of at least 420 degrees, 
together with a specific gravity of 25.8. 

At 350 to 400 degrees Fahrenheit, lubricating 
oils are as fluid as kerosene, therefore the adjust¬ 
ment of the feed should be made when the lubri¬ 
cator and its contents are at their normal heat. 
Steam engine oils are unsuitable for the dry heat 


168 GAS AND OIL ENGINE HAND-BOOK 


of motor cylinders in which they are decomposed 
whilst the tar is deposited. 

All oils will carbonize at 500 to 600 degrees 
Fahrenheit, but graphite is not affected by over 
2,000 degrees Fahrenheit, which is the approxi¬ 
mate temperature of the burning gases in an 
explosive engine. The cylinder of these engines 
may attain an average temperature of 300 to 
400 degrees Fahrenheit. So that graphite would 
be very useful if it could be introduced into the 
engine cylinder without danger of clogging the 
valves and could be fed uniformly. These diffi¬ 
culties have not yet been overcome. 

The film of oil between a shaft and its bearing 
is under a pressure corresponding to the load on 
the bearing, and is drawn in against that pres¬ 
sure by the shaft. It might not be thought 
possible that the velocity of the shaft and the 
adhesion of the oil to the shaft could produce a 
sufficient pressure to support a heavy load, but 
the fact may be verified by drilling a hole in the 
bearing and attaching a pressure gauge. 

Lubrication of Oil Engine Cylinders. On 
account of the rapid decomposition of the lubri¬ 
cating oil in gasoline and kerosene engine cylin¬ 
ders, it is very important that an oil should be 
selected which does not vaporize or carbonize 
easily and leave much residue. A pressure sight- 
feed lubricator should be employed, and no more 
lubricating oil used than is absolutely necessary. 


GAS AND OIL ENGINE HAND-BOOK 169 


For some reason gasoline and kerosene engines 
give more trouble in this connection than gas 
engines. One reason is that the hydrocarbon 
vapor of an oil engine affects the lubricating oil 
in a different manner to the explosive mixture of 
a gas engine. 

Lubrication, Over or Improper. Smoke 
coming from the exhaust of a gas or oil engine is 
due to one of two conditions: Over-lubrication— 
too much lubricating oil being fed to the cylinder 
of the engine—or too rich a mixture, that is, too 
much gasoline and an insufficient supply of air. 

The first condition may be readily detected by 
the smell of burned oil and a yellowish smoke. 
The second, by a dense white smoke accom¬ 
panied by a pungent odor. 

If the engine is working properly, the exhaust 
should be almost colorless or with a light blue 
haze. The oil used should be of the highest flash¬ 
point obtainable, as the heat in a gas or oil 
engine cylinder is very dry and intense. 

The effect upon animal or vegetable oils of 
such heat would be to partially decompose the 
oils into stearic acids and oleic acid and the con¬ 
version of these into pitch. 

Mineral oils are not so readily decomposed by 
heat, but at their boiling points they are con¬ 
verted into gas, and any oil, the boiling point of 
which is in the neighborhood of the working 
temperature of the engine cylinder, is useless, as 


170 GAS AND OIL ENGINE HAND-BOOK 

its body is too greatly reduced to leave an effect¬ 
ive working film on the cylinder walls. 

Lubricators. Always ascertain from the 
builder of the engine how many drops of oil per 
minute are necessary for the different working 
parts of the engine. The lubricators or oil cups 
should then be set accordingly. 

It should be remembered that in cold weather, 
when the oil is thick, a different adjustment of 
the lubricators will be necessary from that found 
suitable in warm weather. It is important that 
the lubrication should be regular, and good oil 
used, but not too much. Too much oil will foul 
the igniter points, clog the valves, and interfere 
with the quality of the explosive mixture. For 
this reason the lubricators should always be 
carefully closed when the engine is stopped. If a 
mechanical lubricator is used, examine the 
mechanism sometimes, and do not trust entirely 
to the feed. If a pressure lubricator is used, see 
that the piston or cap is tight, for if not the 
pressure will stop the lubrication. 

It is not only a question of economy in using 
a good lubricant with an engine, but also of 
increasing the net power for effective work. 
This is especially true with the gas engine, for 
we depend on the oil to make the piston and 
rings tight to hold both the compression and 
the high pressure of the explosion. 


GAS AND OIL ENGINE HAND-BOOK 171 


A good oil forms an almost frictionless film 
between the surfaces of the piston, rings and 
walls of the cylinder, or between the shaft and 
the bearing, as the case may be, and thus pre¬ 
vents the metals from coming in direct contact. 

Misfiring, Causes of. Misfiring means failing 
to fire every explosive charge that the engine 
takes. 

One of the most common causes of misfiring 
is an improper mixture of gasoline and air. Too 
much air or too much gasoline will cause mis¬ 
firing. 

Batteries which are almost exhausted will give 
rise to explosions in the engine cylinder which 
seem all the more violent on account of their' 
irregularity. It is perfectly useless to connect a 
set of nearly exhausted cells with a new set, 
either in series or parallel, as it will reduce the 
new cells nearly to the voltage of the exhausted 
ones. 

Examine the battery and all its connections at 
the terminals, and determine whether the battery 
is exhausted or not, or whether there are broken 
connections. It may be that the ignition contact 
points need cleaning or attention otherwise. 
Also ascertain whether the fuel is being fed to 
the engine in proper quantities. It may not be 
getting enough at each charge or perhaps too 
much. 


172 GAS AND OIL ENGINE HAND-BOOK 


Misfiring will also occur from the ignition tube 
being fouled from soot or oil. 

Mixing Valve. For stationary or portable 
gasoline engines where the speed is not being 
constantly changed, mixing valves are specially 



Mixing valve for use with gasoline engine, showing air inlet-valve 
and gasoline needle-valve regulation. 

adapted. A standard type of mixing valve is 
illustrated in Figure 40. It consists of a chamber 
A, valve B, spring C, collar D, valve-stem 
guide E, cover F, gasoline inlet G, needle- 
valve H, thumb-nut J and lock-spring K. 

The gasoline is fed through a suitable pipe 













GAS AND OIL ENGINE HAND-BOOK 173 


from the supply tank to the opening in the seat 
of the valve. The rate of feed or flow of the 
gasoline is regulated by means of the needle- 
valve. The inductive action of the engine piston 
draws the valve from its seat and at the same 
time uncovers the opening in the valve-seat lead¬ 
ing from the gasoline supply pipe and allows of 
the flow of a small quantity of gasoline as the 
case may be. 

The gasoline mixes with the air drawn through 
the opening in the valve-seat and the friction of 
passing around the narrow space between the 
valve and its seat insures a uniform mixture of 
gasoline and air. The air is drawn through the 
mixing valve in the direction indicated by the 
arrows. 

Nordberg High Compression Oil Engine. 

—The Nordberg engine is of the two-stroke 
cycle type and resembles the Diesel engine in so 
far as concerns the method of ignition by the heat 
of the highly compressed air. The compression 
pressures are about 450 lbs. But a three-stage 
high-pressure air compressor for 1000 lbs. pres¬ 
sure for injecting and atomizing the fuel is not 
used. The fuel is injected mechanically by a 
small pump and discharges through a new type 
of atomizing head which successfully subdivides 
and atomizes the oil. The success of the engine 
is due largely to the effective working of this 
atomizing head. The elimination of the high 


174 GAS AND OIL ENGINE HAND-BOOK 


pressure compressor with its intercoolers simpli¬ 
fies; the installation in small plants for which these 
engines are designed. 

Ignition .—The Nordberg oil engine ignites 
its fuel on its own compression. It therefore 
requires no hot bulb, torch or other auxiliary 
ignition apparatus. 

The process of ignition is as follows: With 
the piston on the return stroke, the air entrapped 
in the cylinder is compressed to a pressure of 
approximately 450 lbs. per sq. in. and at the end 
of the stroke the charge of fuel oil is injected 
through the fuel nozzle located in the cylinder 
head and ignition occurs at once, owing to the 
high temperature of the compressed air. 

Exhaust and Scavenging .—When near the end 
of the working stroke the piston uncovers the 
exhaust ports, and after these have been opened 
a certain amount the scavenging port is also 
uncovered by the piston, and fresh air from the 
scavenging space is blown into the cylinder and 
through the exhaust openings, thus cleaning out 
the burned gases and providing fresh air for the 
next cycle. A clear understanding of the action 
taking place within the cylinder during the 
period of a cycle can be obtained by an inspec¬ 
tion of Figures 40 a and 406, both of which are 
self-explanatory. 

Fuel Supply and Regulation .—The fuel oil 
is supplied to the fuel nozzle under the required 


! 



FIG. 40a 

Longitudinal section of Nordberg high compression oil engine 

N—Fuel nozzle J—Water jacket 

E—Exhaust chamber B—Scavenging port 




















































































































































176 GAS AND OIL ENGINE HAND-BOOK 


pressure by means of the fuel pump driven by 
an eccentric on the crank shaft as shown in Fig¬ 
ure 40b. 

The quantity of fuel required to be delivered 
to the nozzle in order to maintain a uniform speed 
is controlled by means of a centrifugal shaft gov¬ 
ernor which acts on the fuel pump through a 
rod and determines the amount of oil which is 
by-passed by the pump, or in other words the 
amount not used. The by-passed oil is discharged 
through a sight glass and gives the operator a 
quick check on the working of the oil pump. It 
is claimed by the builders, the Nordberg Manu¬ 
facturing Company of Milwaukee, Wis., that this 
method of control gives a regulation of 2 per 
cent from no load to full load. 

The fuel oil is delivered through a small pipe 
to the atomizer or nozzle, which is bolted to the 
cylinder head as shown in Figures 40 a and 40b. 
This device breaks up the fuel into fine particles 
and distributes it evenly over the entire section 
of the cylinder in the same manner as the fuel 
valve using highly compressed air in the Diesel 
engine. The fuel pump is a simple plunger pump 
of very strong construction. The plunger has a 
constant stroke, receiving its motion from a driv¬ 
ing cam operated by an eccentric on the crank 
shaft. The capacity of the pump is for a much 
greater quantity of oil than the engine would 
ever use, but, as before stated, the amount of oil 


































































































































































































































178 GAS AND OIL ENGINE HAND-BOOK 


actually delivered to the fuel nozzle is always 
under the control of the shaft governor. The 
fuel pump and driving cam are located in a cast 
iron box kept filled with oil, so that the pump 
operating mechanism is continually submerged 
in oil. The pump is supplied with fuel oil from 
a reservoir fitted with compartments for the dif¬ 
ferent kinds of fuel oil to be used. This reser¬ 
voir stands at a level sufficiently high to allow 
the fuel oil to flow by gravity to the oil pump. 
The fuel reservoir is kept supplied by means of a 
small oil pump driven from the engine. This 
pump lifts the fuel oil from the underground 
storage tank and delivers it into the reservoir. 
The overflow from this fuel reservoir can be piped 
back to the underground tank. Kerosene or dis¬ 
tillate is used in this engine only in starting, or 
when the regular fuel oil happens to be heavy or 
viscous. All that is required in order to change 
from distillate to the regular fuel oil is the turn¬ 
ing of a three way cock to the proper position. 

Starting .—The Nordberg oil engine is started 
by the admission of compressed air at a pressure 
of 250 lbs. per sq. in. into the cylinder behind the 
piston. The starting valve is of the quick open¬ 
ing type and is manipulated by the operator who 
gives the cylinder the proper charge of com¬ 
pressed air for the right portion of the stroke. 
After one or tw T o revolutions the operator starts 
the fuel pump by means of a lever which throws 


GAS AND OIL ENGINE HAND-BOOK 179 


the pump cam into connection, thus starting the 
flow of fuel oil to the cylinder. The engine 
usually fires on the third or fourth revolution. 
The compressed air required for starting is sup¬ 
plied from a steel storage tank which in turn is 
kept charged with air by means of a two-stage air 
compressor designed for a working pressure of 
250 lbs. per sq. in. and is provided with an inter¬ 
cooler. 

This air compressor may be driven by a belt 
from the engine shaft, or from an electric motor. 
It is used only for short periods when re-charging 
the air storage tank after the engine has been 
started. The method by which the scavenging 
air is supplied to the cylinder is as follows: The 
space between the piston and the front end of the 
cylinder is used as a compression space. On the 
back stroke of the piston, air is drawn into this 
space through a piston valve driven by an eccen¬ 
tric on the crank shaft. On the forward stroke 
of the piston this air is slightly compressed in 
the space between the front cylinder head and 
piston until at the end of the stroke the scav¬ 
enging port is opened by the piston as described. 

Cooling System .—The cylinder is water-jack- 
eted and the jacket spaces are provided with 
hand-holes for cleaning. The quantity of water 
required for cooling varies from 4 to 7 gallons 
per brake horse power hour, depending upon the 
temperature of the water. There are no valves 


180 GAS AND OIL ENGINE HAND-BOOK 


in the cylinder head to be cooled, the head being 
a simple symmetrical casting and not subject to 
cracks due to unequal expansion. One of the 
principal characteristics of this engine is the ab¬ 
sence of all valves and valve gear, there being 
but one valve on the engine, and that is the piston 
valve for the admittance of scavenging air to the 
front end of the cylinder. 

Lubrication .—The engine is provided with a 
double compartment power driven lubricating 
pump having several independent outlets. One 
compartment of the pump is supplied with cyl¬ 
inder oil and lubricates the cylinder and scav¬ 
enging valve. The other compartment is pro¬ 
vided with several outlets which lead to the vari¬ 
ous bearings of the engine. 

Oil Engine Cycle. The cycle or series of 
operations which take place in the vaporizing 
and combustion chambers of one of the usual 
forms of oil engine is illustrated in Figure 41. 
Before starting the engine the vaporizing cham¬ 
ber, shown to the left in the drawing, is brought 
to a red heat by means of a Bunsen burner, this 
heat being afterwards maintained by the combus¬ 
tion of the gases in the vaporizing chamber. 

During the suction stroke of the piston, a jet 
or spray of oil is forced through the opening in 
the nozzle at the bottom of the vaporizing cham¬ 
ber by means of a pump, and upon coming 
into contact with the hot interior of the chamber 


GAS AND OIL ENGINE HAND-BOOK 181 


is at once transformed into vapor, at the same 
time a charge of pure air is drawn into the 
cylinder of the engine through the valve shown 
at the bottom of the combustion chamber. The 
piston then compresses the charge of air, forcing 
a portion of it 
into the vapor¬ 
izing chamber 
and as soon as 
the explosive 
charge has 
reached the 
proper degree 
of temperature 
spontaneous or’ 
self -ignition 
takes place. 

Oil Vapori¬ 
zation, Meth¬ 
ods of. Oil en¬ 
gines have two 
methods of va¬ 
porization, one 
in which the oil 
is injected directly into the cylinder and the 
other where it is drawn in with the air. The 
mixture of oil vapor and air being carried on by 
compression in the cylinder, ignition is caused by 
an electric or tube igniter. The heat from the 
exhaust is sometimes utilized to raise the temper- 



FIG. 41 

Cycle of oil engine, showing the various 
operations during the cycle. 












































182 GAS AND OIL ENGINE HAND-BOOK 


ature of the chamber through which the oil 
passes to the cylinder, which, with the heat 
caused by compression, is sufficient to cause 
vaporization and a proper mixing with the air to 
form an explosive mixture, the chamber, which 
is heated by the exhaust in operation, being first 
heated by a burner. 

The different types of vaporizers may be 
classed as follows: 

A vaporizer into which the charge of oil is 
injected by a spraying nozzle connected to the 
combustion chamber through a valve. 

A vaporizer into which the oil is injected, 
together with a small volume of air, the greater 
volume of air entering the cylinder through a 
separate valve. 

A vaporizer into which the oil and all the air 
supply is drawn, but without a spraying device. 

A form of vaporizer into which the oil is 
injected directly, air first being drawn into the 
cylinder by means of a separate valve, the explo¬ 
sive mixture being formed only with the com¬ 
pression. 

Oil Vaporizer, Crude. On the Pacific coast 
crude oil is new largely used for fuel. In many 
instances the crude oil is vaporized in a separate 
apparatus and is then used in an ordinary gas 
engine. This apparatus is usually separate from 
the engine, the oil being entirely vaporized before 
it reaches the engine. Such vaporizing apparatus 


GAS AND OIL ENGINE HAND-BOOK 183 


are made by various manufacturers, but in gen¬ 
eral principle they are similar. The heat of the 
exhaust gases from the engine is utilized to heat 
the vaporizer into which the crude oil is intro¬ 
duced, where it is converted into gas. 

The fuel to be vaporized enters a ribbed 
chamber through suitable openings, and the gas 
is drawn from the chamber through a separate 
connection to the engine cylinder. The exhaust 
gases from the engine are connected to an outer 
chamber and pass around, heating the inner 
chamber to a temperature necessary for vaporiza¬ 
tion. Provision is made to draw off the residue 
of the crude oil, which is not capable of vapor¬ 
ization, and provision is also made to cleanse the 
vaporizing chamber of deposits of carbon and 
other non-combustible matter. 

Oil Vaporizers. The usual form of oil vapor¬ 
izers consists of a heated chamber in which the 
charge of oil is transformed into vapor before 
being mixed with the air in the cylinder of the 
engine. 

Vaporizers vary considerably in their construc¬ 
tion and operation. 

In some the oil strikes the air as it enters, in 
others a pump forces a jet of oil against the sides 
of the vaporizing chamber and is in this manner 
broken up into spray and mixed with the hot air, 
which rapidly vaporizes it. 

A form of oil vaporizer is illustrated in 


184 GAS AND OIL ENGINE HAND-BOOK 


Figure 42, in which the charge of oil is sprayed 
directly into the vaporizing chamber by means of 



FIG. 42 

Vaporizing chamber of oil engine, showing the flanges or ribs in 
the chamber and oil feed to the vaporizing chamber. 


a pump, the oil passing to the chamber through 
the small pipe shown in the left-hand view in the 
drawing. 

Overheating, Causes of. The effect of over¬ 
heating is to burn up the lubricating oil in the 
cylinder. This causes a smell of burning and an 
odor of hot metal. There is sometimes a slight 
smoke and the engine will make a knocking 
sound. 

A simple test in the case of an overheated 
engine is to let a few drops of water fall on the 
head of the cylinder. If it sizzles for a few 
moments the overheating is not bad, but if the 
water at once turns into steam, the case is 
serious. 

As soon as any of the above symptoms are 
noticed: 




















GAS AND OIL ENGINE HAND-BOOK 185 


The engine should be stopped at once. 

Kerosene should be copiously injected into the 
cylinder and the engine turned by hand to free 
the piston-rings. 

Insufficient lubrication increases the friction 
between the piston and cylinder, and so generates 
extra heat. Bad or unsuitable lubricating oil may 
have the same effect. 

Too rich a mixture also causes increased 
heat. 

Pistons. The piston used in a gasoline engine 
cylinder is usually of the single-acting or trunk 
type. It is made of an iron casting which is a 
good working fit in the cylinder. Around the 
upper end of the piston three or four grooves are 
cut, and in these grooves the piston-rings fit. 
The rings are made of cast iron, and the bore of 
the ring being eccentric to its outer diameter, 
there is a certain amount of spring in them, and 
so pressure is caused against the cylinder wall, 
preventing any of the expanding gases passing 
the piston. 

The lubrication of the piston-rings is very 
important, for on that depends the proper work¬ 
ing of the piston in the cylinder. In single¬ 
cylinder engines, the piston-rings require frequent 
attention, and kerosene should be injected into 
a suitable opening at frequent intervals. Occa¬ 
sionally the piston should be taken out, and the 
rings cleaned with a brush and kerosene. 


186 GAS AND OIL ENGINE HAND-BOOK 


Piston Displacement. The piston displace¬ 
ment. of an engine is the volume swept out by 
the piston, and is equal to the area of the cylin¬ 
der multiplied by the stroke of the piston. The 
expression, cylinder volume, is sometimes con¬ 
founded with the term piston displacement. 
This is erroneous, as the cylinder volume is 
equal to the piston displacement, plus the com¬ 
bustion space in the cylinder head. 

Pistons, Length of. For vertical cylinder gas 
or oil engines the length of the piston should not 
on any account be less than one and one-quarter 
its diameter, while a length equal to one and 
one-third or even one and one-half diameters is 
better. For engines with horizontal cylinders the 
length of the piston, in any case, should not be 



less than one and one-half diameters, and if pos¬ 
sible one and two-thirds diameters or over. 

A typical piston for gas or oil engine use is 
shown in Figure 43. 










GAS AMD OIL ENGINE HAND-BOOK 187 


Piston-rings. To ensure proper compression„ 
it is absolutely essential that the piston-rings 
should be kept lubricated, consequently if the 
engine has been standing for some time, the 
compression at the start is often poor. Any fail¬ 
ure in the lubrication while running will, of 
course, have the same effect, such, for example, 
as in the case of overheating, or when the supply 
is intermittent. Sometimes the piston-rings get 
stuck in their grooves with burnt oil, through 
overheating, and the compression escapes past 
them. Thorough cleaning with kerosene and 
fresh lubricating oil will settle the matter. It 
engines where the rings are not pinned in posi¬ 
tion, the slots may sometimes work round so as 
to coincide. 

A new method of making piston-rings has 
recently been introduced, for which several 
important advantages are claimed. The rings 
are turned and finished to the correct size of the 
cylinder in the usual way, and are afterwards 
automatically hammered on their inside surfaces, 
to give them the necessary elasticity. 

The hammering is made heaviest and by this 
method a stress is set up diametrically opposite 
to the ring joint, and the hammering gradually 
reduced in both directions till the joint is reached. 

Piston-rings, Method of Turning. A pat¬ 
tern should be made from which to cast a blank 
cylinder or sleeve with two projecting slotted lugs 


188 GAS AND OIL ENGINE HAND-BOOK 


on one end to bolt same to face plate of lathe. 
This blank should first be turned off outside to 
the required diameter, making it, of course, 
sufficiently larger to allow for the cut in the rings, 
after cutting from the blank. The blank should 
then be set over eccentric sufficiently to allow the 
thick side of the rings to be twice the thickness 
of the thin side after turning. The inside of the 
blank can then be bored out, and the rings cut 
off to the exact thickness required with a good 
sharp cutting off tool. A mandril or arbor 
should be made with two cast iron washers or 
collars t to fit on it, one fastened to the mandril 
and the other loose, with lock nut on mandril 
with which to tighten up the loose collar. After 
the rings have been sawed open and a piece cut 
out the required length, they can be placed in a 
collar or ring about 1-32 to 3-64 of an inch 
larger than the cylinder bore, and slipped on to 
the mandril one at a time of course, with the 
loose collar and nut off the same. The loose 
collar and nut can then be put on the mandril, 
the ring clamped tightly between the two collars, 
the mandril put in the lathe and the ring turned 
off, without leaving any fins or having to cut the 
ring off afterward as is done in many cases. 
This is the only way in which a perfectly true 
ring can be made. 

Figure 44 shows two forms of piston-rings, the 
cut or slot in one being of the type known as the 


GAS AND OIL ENGINE HAND-BOOK 189 


ship-lap and the other as the miter-cut. Both 
forms are in use, the ship-lap form, however, is 
the more expensive to make. 

Piston Velocity. The rate of travel or speed 
of the piston of a gas or oil engine is from 600 to 
750 feet per minute. 

To ascertain the piston velocity in feet per 



Side and end elevation of piston-rine^, showing ship-lap and 
miter-cut types. 

minute, multiply the stroke of the piston in 
inches by the number of revolutions per minute 
and divide the result by 6. 

Example: Required the piston velocity of an 
engine with 9-inch stroke, at 400 revolutions per 
minute. 

Answer: Nine multiplied by 400 equals 3,600, 










190 GAS AND OIL ENGINE HAND-BOOK 

































































Gas AND OIL ENGINE HAND-BOOK 191 


this divided by 6 gives 600 feet per minute as the 
piston velocity. 

Portable Oil Engines. Portable gasoline and 
kerosene engines are used for a variety of pur¬ 
poses. Such engines in connection with circular 
saws, electric light or pumping outfits are found 
very useful. Portable engines are also used for 
agricultural work, such as operating threshing 
machines, feed cutters and other farm machinery. 
Figure 45 shows a portable oil engine mounted 
upon a truck with wooden frame and steel wheels 
and running gear. The engine, cooling appara¬ 
tus and battery are clearly shown in the draw¬ 
ing. 

As portable engines require to be frequently 
moved from place to place, the design of the 
outfit should be as light as possible and yet sub¬ 
stantial in construction, so that it may be moved 
from one place to another in the shortest possible 
time and with the least expense for transporta¬ 
tion. 

As portable engines are often in places where 
a supply of water is not available, the water¬ 
cooling apparatus forms an important part of the 
outfit. 

Another foJm of portable engine is shown in 
Figure 46, which is simply mounted on skids 
and may be moved from place to place by two 
l e A *sons. Such an outfit is of much smaller capac- 
u 7 than the one previously described and illus- 


192 GAS AND OIL ENGINE HAND-BOOK 





























































GAS AND OIL ENGINE HAND-BOOK 193 


trated, but is found useful for many purposes 
where small power is needed. 

Premature Ignition, Causes of. Too great 
a degree of compression of the charge, an incan¬ 
descent deposit of soot or foreign substance in 
the combustion chamber, from slow or incom¬ 
plete combustion of the previous charge, which 
remains sufficiently heated to fire the new charge 
before the completion of the compression stroke, 
burning gases drawn from the exhaust-pipe into 
the combustion chamber, from the overheating 
of the exhaust valve. Premature ignitions are 
also attributed to the use of low-flash test oils for 
lubricating the cylinder, and too little air in the 
charge will also cause too rapid firing, or in the 
case of the primary form of electric ignition from 
overheated igniter points. 

Primary-spark Coil. This form of induction 
coil is generally used for ignition purposes on gas 
and gasoline engines fitted with a mechanical 
make-and-break form of spark, which is located 
within the combustion chamber of the engine 
itself. 

It consists of two principal parts, a core, made 
of a bundle of soft iron wire, and a coil of wire 
around this core composed of from 3 to 5 layers 
of turns of insulated copper wire, varying in 
diameter from No. 16 to No. 12, B. & S. Gauge, 
according to the battery conditions under which 
the coil has to operate. The iron core may vary 


194 GAS AND OIL ENGINE HAND-BOOK 


from three-eighths of an inch in diameter and 
G inches long, to three-fourths of an inch in 
diameter, and 12 to 15 inches long, depending 
upon the intensity and capacity of the spark 
required. 

Primary-spark Plug. The construction of 
one of the usual forms of make-and-break pri¬ 
mary-spark plugs is clearly shown in Figure 47. 
The upper and fixed electrode is insulated by 



FIG. 47 

Primary-spark plug, showing fixed and movable electrodes and 
platinum contact-points. 


means of mica or lava washers and is secured in 
place by means of a lock nut and washer. The 
movable electrode has a coil spring around its 
outer end, one end of the spring secured to the 
spindle of the electrode and the other to the hub 
of a small trigger on the extreme end of the 
spindle. This construction allows for any wear 
on the contact-points and at all times ensures a 
good contact between them. 













GAS AND OIL ENGINE HAND-BOOK 195 


Prony Brake. This simple device gives the 
actual energy in foot-pounds per minute delivered 
by the engine at its driving shaft. 

The apparatus for making a brake test is fully 
illustrated in Figure 48. Two brake-blocks A 
partially surround the pulley P and are attached 
to the clamping pieces B and C, which hold the 
brake-blocks upon the pulley by means of the 
bolts D, springs E and thumb-nuts F. The 
lever G is double-ended for the dual purpose of 
balancing itself and also supplying a place of 
attachment for the weight W to balance the 
weight of the spring scale S. 

In using this form of Prony brake, the engine 
is started in the direction indicated by the arrow 
on the drawing, the brake-blocks A are then 
tightened by means of the springs E and thumb- 
nuts F. Then the reading of the spring scale S 
and the speed of the pulley P are taken. 

The engine should be tested at varying speeds 
and the pull on the spring scale S noted for each. 

The actual horsepower can then be calculated 
for each test and what is known as the critical 
speed of the engine determined, that is the speed 
at which the engine develops the greatest brake 
horsepower. 

The following formula gives the actual horse¬ 
power obtained from the results of a Prony brake 
test: Let L be the length of the scale lever in 
inches, and S the pull indicated by the spring 


196 GAS AND OIL ENGINE HAND-BOOK 
































GAS AND OIL ENGINE HAND-BOOK 197 


scale in pounds. If N be the number of revolu¬ 
tions per minute of the pulley R and B.H.P the 
actual or brake horsepower of the engine, then 

b,h,p = l xsxn 

63,025 

Remington Oil Engine. The Remington 
oil engine is of the vertical type, operating on 
the two-stroke cycle, the fuel being introduced 
into the combustion chamber as a liquid and 
gasified within this chamber. The engine is 
valveless, the gases being moved into and out of 
the cylinder through ports uncovered by the 
movement of the piston, which itself performs 
also the function of a pump. The action is as 
follows: 

On the up-stroke of the piston a partial 
vacuum is created in the enclosed crankcase, 
causing air to rush in when the bottom of the 
piston uncovers the inlet port seen directly un¬ 
der the exhaust port (23), Figure 48a. On the 
next down-stroke this air is compressed in the 
crankcase to about four or five pounds pressure 
per square inch. Meanwhile the mixture of oil, 
vapor and air already in the cylinder is burning 
and expanding. When the piston approaches 
the end of its down-stroke, it uncovers the ex¬ 
haust port (23), permitting the burnt charge 
to escape, until its pressure reaches that of the 
atmosphere. Directly afterward the transfer 
port on the opposite side of the cylinder is un- 



198 


GAS AND OIL ENGINE HAND-BOOK 



FIG. 48a 


Names 


13 

Oil spraying nozzle. 

20 

14 

Control lever. 

21 

15 

Hand hole cover. 

22 

16 

Crankpin brasses. 

23 

17 

Flywheel. 

24 

IS 

Governor weight. 

25 

19 

Cam. 



of Tarts. 

Stud carrying governor weight. 
Crankcase end plate. 

Wrist pin bushing. 

Exhaust pipe flange. 

Speed control segment. 

Bracket carrying control lever. 











GAS AND OIL ENGINE HAND-BOOK 199 


covered by the piston, thereby allowing a por¬ 
tion of the air compressed in the crankcase to 
rush into the cylinder, where it is deflected up¬ 
wards by the shape of the top of the piston and 
caused to fill the cylinder, thereby expelling the 
remainder of the burnt charge. The piston now 
starts upward, compressing the fresh charge of 
air into the hot cylinder head. Near the end 
of the stroke a small oil pump, mounted on the 
crankcase and controlled by the governor, in¬ 
jects the proper amount of oil through the noz¬ 
zle (13), Figure 48b, into the compressed and 
heated air. 

This oil is atomized in a vertical direction 
through a hole near the end of the nozzle. It 
is therefore vaporized and gasified before there 
is a possibility of its reaching the cylinder walls. 

The spray of oil is ignited by the nickel steel 
plug (12), which is kept red hot by the ex¬ 
plosions, because the iron walls surrounding it 
are protected from radiation by the hood (11). 
By the burning of the oil spray in the air the 
pressure is gradually increased and the piston 
forced downward, this being the power or im¬ 
pulse stroke. Near the end of the down-stroke 
the exhaust port is again uncovered and the burnt 
gases discharged. 

The operations above described take place in 
the cylinder and crankcase with every revolution. 
Each up-stroke of the piston draws fresh air 
into the crankcase and compresses the air trans¬ 
ferred to the cylinder. Each dow r n-stroke is a 


200 


GAS AND OIL ENGINE HAND-BOOK 



FIG. 48b 


Names of Parts. 


1 Cylinder head. 7 

2 Cylinder. 8 

3 Piston. 9 

4 Wrist pin. 10 

5 Connecting rod. 11 


6 Counter balance weights. 12 


Main bearing cap. 
Crankshaft and crankpin. 
Crank oil hole. 

Crankcase. 

Hood on cylinder head. 
Igniter plug of nickel steel. 








GAS AND OIL ENGINE HAND-BOOK 201 


power stroke and at the same time compresses 
the air in the crankcase preparatory to trans¬ 
ferring it to the cylinder by its own pressure at 
the end of the stroke. 

The same volume of air enters the cylinder 
under all conditions, and the power is regulated 
by modifying the stroke of the oil pump, which 
may be done by hand or automatically by the 
governor in the flywheel. 

Governor and Control. The governor is of 
the centrifugal type. It has an L-shaped weight 

(18) , Figure 48b, pivoted to the piece (20) at¬ 
tached to the flywheel. As the engine speed 
increases the weight (18) tends to swing out¬ 
ward toward the flywheel rim, and thereby moves 
the arm attached to it so as to shift the cam 

(19) along the crankshaft toward the left in the 
figure. 

This cam turns with the shaft, and operates 
the kerosene oil pump. According to the posi¬ 
tion of the cam on the shaft, it will impart to the 
pump plunger a long or a short stroke, thereby 
injecting more or less oil into the cylinder. The 
long lever pivoted on the bracket (25) moves 
with the cam (19) and is used for controlling the 
engine’s speed by hand. To stop the engine 
the handle (14) of the lever is pulled towards 
the flywheel, thereby interrupting the pump 
action altogether. 

The handle of the control lever can be fitted 
with an adjustable speed regulator when re¬ 
quired. This device is for use on marine engines 


202 GAS AND OIL ENGINE HAND-BOOK 

to enable the operator to slow down the engine. 
The speed regulator does not interfere with the 
action of the governor, but acts in conjunction 
with it. Whatever the speed of the engine may 
be, it is under the control of the governor. The 
engine can be controlled from the pilot house 
if such an arrangement is desirable. 

All Remington oil engines are built to op¬ 
erate on all grades of ordinary kerosene oil, 
while several sizes are built especially to operate 
on lower grade, semi-refined fuels, which have a 
variety of names and composition, such as fuel 
oil, Diesel oil, distillate, solar oil, gas oil, etc. 

Starting. To start the engine, the hollow 
cast-iron projection rising from the cylinder 
head is heated by the kerosene torch furnished 
with the engine. When it is hot, a single charge 
of oil is injected into the cylinder by working 
the hand lever connected with the pump. The 
flywheel is now turned smartly backward, there¬ 
by compressing the charge, which ignites before 
the piston reaches the highest point, and starts 
the engine in the forward directon. 

After the engine has been started the starting 
torch may be extinguished. Ignition will take 
place continuously and the engine will not miss 
fire under varying loads. 

Cylinder. The cylinder is provided with a 
water jacket extending practically its full length. 
This insures thorough cooling of the piston and 
increases the efficiency of the lubrication. 

This water jacket is provided with two long 


GAS AND OIL ENGINE HAND-BOOK 203 


hand hole plates on opposite sides of the cylin¬ 
der, which may be conveniently removed for in¬ 
specting and removing sediment from the water 
jacket space. 

Ignition. Rising from the center of the 
head is a hollow cast-iron projection, which con¬ 
tains the nickel steel igniter plug by which the 
oil gas is ignited. This plug is practically inde¬ 
structible by heat, and as it is permanently 
located at an exact point found correct by trial, 
it fires the charge at the right moment under all 
conditions. 

Fuel Pump. The fuel pump is made of bronze. 
The valves are made of bronze and are specially 
designed with very large areas and are very care¬ 
fully fitted and ground. The plunger is made of 
tool steel and is hardened and ground. A bronze 
cup strainer is attached to the lower end of the 
pump to prevent sediment or foreign matter from 
reaching the pump valves. 

Repairing a Gas or Oil Engine. The piston 
should be thoroughly washed with kerosene. 
When putting the piston back in the cylinder, 
each ring should be put separately in exact posi¬ 
tion in its groove as regards the dowel-pin (if 
any) in the ring groove before the ring enters 
the cylinder. The piston, the rings, and the 
inside of the cylinder should all be carefully 
cleaned and well lubricated with proper oil before 
the piston is again put in place. Where the rings 
require cleaning, this should be done by washing 
with kerosene. If the piston-rings require to be 


204 GAS AND OIL ENGINE HAND-BOOK 


taken off the piston, they should be sprung open 
by having pieces of sheet metal about one- 
sixteenth of an inch thick and about one-half 
inch wide inserted between the ring and the 
body of piston. 

The inlet and exhaust-valves should be fre¬ 
quently taken out, cleaned and examined, and, if 
necessary, reground in. Finely-powdered emery 
or tripoli are very satisfactory to grind the valves 
in with. 

Care should be taken, in replacing the valves, 
that they are clean and free from rust or carbon, 
and are allowed to drop on their seats freely and 
do not stick in their guides. 

The crank-shaft bearings will occasionally 
require taking up as they show signs of wear and 
commence to knock or pound. For this adjust¬ 
ment, liners are placed between the cap and the 
lower half of the bearings. These liners can be 
occasionally reduced in thickness, so that the cap 
is allowed to come down closer to the shaft. 

Secondary Coil. Any form of electrical igni¬ 
tion requires some outside source of electric 
energy such as a generator or battery to produce 
a spark in the combustion chamber of the motor. 
A primary or secondary induction coil is neces¬ 
sary in connection with the source of electric 
energy to give a spark of sufficient intensity to 
properly ignite the compressed charge in the 
combustion chamber of the engine. This method 


GAS AND OIL ENGINE HAND-BOOK 205 


of ignition provides a means of regulating the 
motor speed by advancing and retarding the point 
of ignition, or time of igniting the explosive charge. 

The coil first mentioned is known as a primary- 
spark coil, from the fact that the spark or arc is 
produced by the direct effect of the battery or 
generator current flowing in the coil. This form 
of spark will not arc or jump across a space 




FIG. 49 


Secondary-spark circuit, showing coil spark plug, battery and 


commutator,! 


between two points, but simply occurs between 
the contact-points on the breaking of the contact. 

The second form of induction coil is generally 
known as a secondary-spark coil, because the arc 
or spark is produced in the secondary winding of 
the coil, and will jump or arc across a space 
between two fixed points, without the points first 
coming in contact. 

Figure 49 shows the wiring circuit for a gas or 































206 GAS AND OIL ENGINE HAND-BOOK 


oil engine equipped with the secondary or jump- 
spark form of electrical ignition. The battery, 
commutator, spark coil and spark plug are 
plainly indicated, also the wiring connections 
from the spark coil to the engine and between 
the coil, battery and commutator. 

Smoke from Cylinder, Cause of. If black 
smoke comes from the cylinder, it may arise 
from leaky piston, overheating, w^ant of or excess¬ 
ive lubrication, too rich mixture, faulty combus ¬ 
tion, faulty ignition. 

Solders and Spelters. Solders and spelters 
for use with different metals, and their propor¬ 
tional parts by weights are 


Solder for: 

Electrician’s use.1—Tin, 1—Lead. 

Gold.24—Gold, 2—Silver, 1—Copper. 

Platinum.1—Copper, 3 Silver. 

Plumber’s—Hard . . . 1—Lead, 2—Tin. 

Soft.3—Lead, 1—Tin. 

Silver—Hard.1—Copper, 4—Silver. 

Soft.1—Brass, 2—Silver. 

Tin—Hard.2—Tin, 1—Lead. 

Soft. t .. 1—Tin, 1—Lead. 

Spelter for: 

Fine brass work.8—Copper, 8—Zinc, 1—Silver. 

Common brass. .... .1—Copper, 1—Zinc. 

Cast iron. 4 —Copper, 3—Zinc. 

Steel.3—Copper, 1—Zinc. 

Wrought iron.2—Copper, 1—Zinc. 


Starting a Gas Engine. If an incandescent 
tube is used for the ignition, the Bunsen burner 
should first be lighted. While the tube is being 
heated, oil up all the working parts of the 
engine. 














GAS AND OIL ENGINF HAND-BOOK 207 


If electric ignition is used, close the battery 
switch. 

Next, open the gas valve so as to admit a 
charge of gas into the inlet-valve chamber, along 
with the air, then give the flywheels four or five 
quick turns until the engine starts. 

Open the lubricator on the cylinder and see 
that it is adjusted so as to allow about 10 drops 
of oil to flow per minute. 

The water in the cooling tank should always 
be at least 6 inches above the overflow pipe from 
the top of the cylinder jacket. 

If the engine does not ignite its first or second 
charge there is a reason for it, and the cause of 
the trouble should be located. 

Starting a Gasoline Engine. The instruc¬ 
tions given for starting a gas engine apply also to 
a gasoline engine, with the exception that the 
supply of gasoline from the carbureter or mixing 
valve should be regulated according to the instruc¬ 
tions given by the manufacturer of the engine. 

The fuel supply of a gasoline engine is usually 
regulated by means of a needle-valve, which 
should be carefully cleaned at regular intervals. 
In engines using a pump feed, the supply of 
gasoline is usually regulated by adjusting the 
stroke of the pump, or by regulating the opening 
in a by-pass, so that a portion of the fuel is 
pumped through the by-pass and returns t<? the 
supply tank. 


208 GAS AND OIL ENGINE HAND-BOOK 


Starting a Gasoline or Kerosene Engine for 
the First Time. Don’t attempt to start an 
engine the first time until the following points 
are found to be right: 

That there is good compression. 

That the batteries are set up properly and 
wired correctly. 

That a good bright spark is obtained by 
touching the ends of the two wires at the engine 
together. 

That there is a good supply of gasoline or oil 
in the supply tank. 

That the gasoline or oil pump works freely 
and that the gasoline or oil reaches the vaporizer. 

That the inlet and exhaust-valves are not 
stuck, and that they work freely and seat 
quickly. 

Starting a Gas or Oil Engine, General Direc¬ 
tions for. The successful starting or running of 
an engine depends entirely on the mixture of gas 
and air, and proper ignition. 

As all of these are under full control of the 
operator at all times, it lies entirely with him as 
to whether the engine starts and runs properly or 
not. 

The engine cannot start itself, it must be 
started. 

If the above conditions and the' following 
instructions are properly carried on*, the engine 
will start without fail. 


0AS AND OIL ENGINE HAND-BOOK 209 


Before starting up the engine, go over all the 
connections carefully and see that everything is 
in place according to the instructions. 

See that the gasoline tank is full. 

Pump up the gasoline by working the pump 
lever until the feed chamber is full. 

Close the cock in the bottom of the water tank 
and fill the tank to near the top pipe, but not full 
enough to run into the pipe if the weather is 
freezing. 

Never let the water enter the cylinder or valve 
chamber jackets in cold weather until the engine 
has run long enough to become warm. 

Open the burner-valve, first passing a nail or 
match down through a hole in the burner tube, 
and hold it so as to turn the stream of gasoline 
down and fill the burner pan, then close the valve 
and light the gasoline. 

When the gasoline in the pan is burned out, 
open the valve and light the vapor, which should 
burn with a strong, steady blue flame. 

The globe-valve, next to the burner, is to help 
regulate the flame, and should be closed nearly 
tight. 

While the burner is heating the tube, which 
should take from two to three minutes, if it is 
properly regulated, see that the grease cups are 
full. 

Oil up all parts of the engine. Fill the lubri¬ 
cator and start it to feed. 


210 gas and oil engine hand-book 


Turn the engine round by hand several times 
to see that everything is in its proper place, and 
nothing binding. 

Examine the flywheel keys and see that they 
are driven tight. 

When the tube is hot the engine is ready to 
start. 

If electric ignition is used, close the battery 
switch. Almost close the air-valve before start¬ 
ing the engine. 

The object of closing the air-valve is to obtain 
a rich charge and make it surer to explode. 

The amount of fuel can be regulated at will. 

It can be made so weak that it will not 
explode or so strong it cannot be ignited. 

When black smoke issues from the exhaust 
pipe, the mixture is too strong. 

Starting a Kerosene Engine. The methods 
usually employed to ignite the explosive charge 
in the combustion chamber of an oil engine are: 
By means of an electric spark, an incandescent 
tube, or a vaporizing chamber with projecting 
ribs which are kept incandescent by the heat of 
the previous charge. 

The proper heating of the vaporizing chamber 
is the first and most important thing to be 
attended to when starting an oil engine and care 
should be taken that the vaporizer is sufficiently 
hot before attempting to start the engine. 

The Bunsen burner or lamp should be kept 


GAS AND OIL ENGINE HAND-BOOK 211 


burning for five or ten minutes or even longer, 
according to the size of the engine. When the 
vaporizer is sufficiently heated, turn on the fuel 
oil supply and give the flywheels four or five 
quick turns, if all other conditions are right the 
engine should at once start. See that the cylin¬ 
der lubricator and the oil cups on the crank shaft 
bearings are filled before starting the engine, also 
oil the wrist-pin end of the connecting-rod and 
the cam shaft bearings. After the engine is 
started, open the valve in the air-inlet pipe until 
the engine attains its normal speed. 

When electric ignition is useo, he battery 
switch should always be closed before ui attempt 
is made to start the engine. 

With the hot tube form of ignition, the tube 
should always be incandescent before starting the 
engine. 

Always be sure that the supply of water to the 
cylinder jacket is ample. 

With oil engines which operate on the vapor¬ 
izer principle, it is found absolutely necessary to 
heat the fuel before it enters the cylinder. In 
some oil engines it is not necessary to heat the 
fuel before it enters the cylinder, as it is injected 
against a highly heated surface. 

Starting Oil Engines, New Method of. A 
method of starting an oil engine has of recent years 
been used in which alcohol, gasoline, or naphtha is 
burnt for a few minutes instead of kerosene. 


212 GAS AND OIL ENGINE HAND-BOOK 


This method is advantageous in that the engine 
when cold can be started without the use of an 
external heater. The lighter fuel is supplied to 
the vaporizer or cylinder until the vaporizing 
attachment has become heated by the internal 
combustion to the temperature necessary for 
vaporizing the heavier fuel, then the fuel supply 
is changed, the supply of lighter fuel being 
stopped. Where a vaporizer is used in which 
the charge is not explosive until after compres¬ 
sion, an independent electric igniter is used to 
ignite the charge, and is only in operation until 
the vaporizer becomes properly heated. 

Starting Troubles. If, after turning the 
flywheels of the engine four or five times, it 
refuses to start, the trouble may be due to any 
one of the following causes: Loss of com¬ 
pression, faulty ignition, improper mixture, 
water in the cylinder, or oil on the igniter con¬ 
tact-points. 

Sometimes an engine will start readily, but 
dense smoke having a strong odor will issue from 
the exhaust-pipe. This may be an indication 
that the mixture is too rich, although it is fre¬ 
quently due to an excess of lubricating oil in the 
cylinder. To correct the mixture, more air 
should be admitted to the cylinder. 

Failure of an engine to start is more often 
occasioned by too weak than by too rich a mix¬ 
ture. The first thing to do, if regulating the air 


GAS AND OIL ENGINE HAND-BOOK 213 


does not correct it, is to ascertain if the fuel 
supply pipe is free from obstructions. This pipe 
is generally not very large, and is more or less 
crooked. A partial stoppage of the pipe will 
therefore result in a too weak mixture. 

Stopping a Gas or Oil Engine. The first 
things to do when stopping an engine are: 

Shut off the gas or oil supply. 

Close all oil cups or lubricators. 

Switch off the battery or turn out the ignition 
tube burner. 

Wipe off the engine and see that it is in good 
shape for the next run. 

While cleaning the engine examine all nuts 
and bolts, all points needing adjustment. Exam¬ 
ine the condition of the crank shaft and other 
bearings. If they are hot or show signs of heat¬ 
ing, locate the cause if possible and remove it 
before again starting the engine. 

Do not fail to throw the battery switch off 
when the engine is not running, as there is 
always a possibility of short circuiting the battery 
and possibly ruining it in a few hours. 

It will pay to always keep the engine neat and 
clean. Examine the engine occasionally and see 
that everything is working properly. 

If the engine has not to be re-started for some 
days, it is a good plan to turn off the oil supply 
to the cylinder for a short period before stopping, 
as what oil remains will be burnt out, and there 


214 GAS AND OIL ENGINE HAND-BOOK 


is less liability to the gumming of the piston and 
cylinder or valves. 

Stopping Troubles. Some of the principal 
causes of stopping of gas or oil engines are as 
follows: 

Bad design or construction of the engine, 
improper mixture of fuel ana air, defective water 
circulation or insufficient cooling of the cylinder, 
leakage of the piston, leakage of the valves or 
valve joints, improper or insufficient lubrication, 
governor gear defective, back pressure from foul¬ 
ing of the exhaust with residue, ignition mech¬ 
anism worn or defective, imperfect compression 
or combustion, leak in the inlet-pipe, premature 
ignition, misfiring, backfiring, or the ignition 
wrongly timed. 

Tachometer. A tachometer is an instrument 
for indicating the number of revolutions made by 
a machine in a unit of time—usually one minute. 

Tanks, Capacity of Cylindrical. To ascertain 
the capacity in gallons of a cylindrical tank of 
given length, multiply the area of the cross-sec¬ 
tion of the tank in square inches by the length of 
the tank in inches, and divide the product by 
231, the result will be the capacity of the tank 
in gallons. 

Tanks, Installation of Gasoline. The proper 
method of installing the supply tank for a gaso¬ 
line engine is shown in Figure 50. 

The vault for the reception of the supply tank 


GAS AND OIL ENGINE HAND-BOOK 215 


should be walled with brick of good quality and 
well cemented so as to exclude water, the cover 
of the vault should also be water-tight. Shut-off 



cocks and method of piping. 

valves or cocks should be placed in both the 
supply and overflow pipes as shown. The sup¬ 
ply tank should be made of heavy galvanized iron 
or steel and well riveted. 

A screen of fine wire gauze should always be 
fitted in the mouth of the filling opening of the 
supply tank, to prevent the entrance of dirt or 
other foreign substances which may be in the 
gasoline. 

A small vent opening should be made in the 
cap or cover of the filling opening to allow of the 








































216 GAS AND OIL ENGINE HAND-BOOK 

ingress of air, otherwise the gasoline pump will 
not work properly. 

Throttle, Use of. For the purpose of regu¬ 
lating or controlling the speed of gas or oil 
engines, throttling devices are sometimes used to 
choke or partially cut off the supply of explosive 
mixture, being drawn in the cylinder of the 
engine. 

A butterfly-valve or form of throttle commonly 

used for this 
purpose is 
shown in 
ure 51. It 
has a valve- 
chamber A, 
valve B and 
lever CL The 
valve is loca¬ 
ted at any suit¬ 
able point in 

Throttle for regulating the volume of explo- the inlet-pipe 
sive charge to the engine cylinder. L r 

of the engine, 

between the mixing-valve or vaporizer and the 
inlet-valve chamber. 

Two-cycle Engine, Construction of. Fig¬ 
ure 52 shows a vertical cross-section of a two- 
cycle type of marine engine. C is the crank 
chamber. It has two feet, or lugs, D as shown 
in the drawing, for the purpose of attaching it to 
its position in a boat or elsewhere. There is an 












GAS AND OIL ENGINE HAND-BOOK 217 


opening at A for the reception of the mixing- 
valve. The flywheel F, crank shaft G, connecting- 
rod H, piston P, inlet-port B, baffle-plate J and 
exhaust-opening E, are plainly shown in the 
drawing. 

To the top of the piston P is attached a cone- 
pointed projection K. This is on the right-hand 
side and is placed 
there to break 
the electrical cir¬ 
cuit between the 
contact-points of 
the igniter. This 
is effected by the 
cone - point K 
striking the right- 
hand end of the 
lever L, which 
causes the lever 
to rise at that end 
and fall at the 
other, thus 
breaking the con¬ 
tact between it 
and the insulated 
igniter terminal 
M. This break¬ 
age of the circuit causes a spark to occur between 
the leit-hand end of the lever L and the point with 
which it was, a moment before, in contact. This 



FIG. 52 

Vertical cross-section, showing the con¬ 
struction of a two-cycle gas or 
gasoline engine. 



















218 GAS AND OIL ENGINE HAND-BOOK 


action takes place once in each revolution of the 
motor and just before the piston reaches the end 
of its upward stroke. 

The ignition may be retarded or advanced by 
raising or lowering the fulcrum of the lever L, 
by means of the eccentric shown. 

The upper part of the cylinder is incased by a 
water jacket W, as is the cylinder head or 
cover N. 

Two-cycle Engine, Principle of. Figure 53 
gives two diagrammatic views of the operation of 



FIG. 53 

Two-cycle motor diagrams, showing the various operations 
during the cycles. 


a two-cycle gas or oil engine. It shows an inlet- 
valve A, port or passage B, crank case C, 
exhaust opening E and piston P. When the 
piston has reached the position shown in Dia¬ 
gram No. 1, it has forced a charge of explosive 













GAS AND OIL ENGINE HAND-BOOK 219 


mixture from the crank case through the port or 
passage into the cylinder. The piston then 
moves to the position shown in Diagram No. 2, 
and while doing so, closes the port or passage 
and the exhaust opening, the compressed charge 
is then ignited, an explosion occurs and the 
piston is forced out to the position shown in Dia¬ 
gram No. 1. 

The admission of the new charge of explosive 
mixture to the crank case is controlled by the 
action of the piston. As the latter travels away 
from the crank case, it has a tendency to create 
a partial vacuum in the latter. This operation 
draws the inlet-valve inward and admits the new 
charge. 

The baffle-plate shown on the head of the 
piston directs the new charge from the crank case 
towards the combustion chamber end of the 
cylinder, providing as nearly as possible a pure 
charge of mixture and assisting in the expulsion 
of the burned gases left in the cylinder from the 
last explosion. 

As this type of engine draws in a charge of ex¬ 
plosive mixture, compresses it, ignites it and dis¬ 
charges the products of combustion while the 
piston makes one complete travel backward and 
forward, it consequently has a working stroke or 
power impulse every revolution of the crank-shaft. 

Two-cycle Marine Engine. A single cylinder 
two-cycle type of marine engine mounted on a 


220 GAS AND OIL ENGINE HAND-BOOK 


base with reversing gear, propeller and shaft is 
shown in Figure 54. Such outfits are made in 
single units of from lj to horsepower. 

Valves. A valve in a very bad or pitted con¬ 
dition causes bad compression and the exhaust- 
valve should be ground occasionally. After 



FIG. 54 

Two-cycle marine engine, with reversing mechanism, propeller 
shaft and propeller mounted on base plate. 


grinding a valve be sure that there is ample 
clearance between the valve and the lifter. It 
should have not less than one-thirty-second of an 
inch, otherwise when the valve becomes hot it 
will not seat properly, poor compression being 
the result. In grinding a valve there is no occa¬ 
sion to use force, and the grinding should be 
done lightly, the valve being lifted from time to 
time so that any foreign substance in the emery 












GAS AND OIL ENGINE HAND-BOOK 221 


will not cut a ridge in the seat or the valve itself. 
After grinding a valve always wash out the valve 
seat with a little kerosene and be careful that 
none of the emery is allowed to get into the 
engine cylinder. 

Sometimes an engine may suddenly stop from 
the failure of a valve to seat properly. This may 
be due to the warping of the valve through the 
engine having run dry and become hot, or it may 
be from the failure of the valve spring or the 
sticking of the valve-stem in its guides. The 
valve should be removed, and the stem cleaned 
and scraped, or straightened if it requires it, 
until it moves freely in the guide, and the spring 
is given its full tension. If the valve still leaks 
so that the engine will not start or develop suffi¬ 
cient power, the valve will have to be ground 
into its seat. 

Valves which need re-seating should first be 
ground in place with fine emery and oil, then 
finished with tripoli and water. 

Valves and Valve-chambers. The dimen¬ 
sions of the inlet and exhaust-valve openings are 
governed by the diameter of the cylinder and ti: ~ 
piston velocity in feet per minute. The form ot 
valve-chamber in general use is made separate 
and bolted to the cylinder. The valve-chamber 
can then be entirely renewed if necessary and at 
small expense. Other forms of valve-chambers 
have the valves placed horizontally in the cyl- 


222 GAS AND OIL ENGINE HAND-BOOK 


inder head. In any case the valves should be 
brought as close as possible to the inside of the 
cylinder, the clearance space in the ports being 
reduced to a minimum. 

In engines of large size the inlet and exhaust- 
valve chamber is surrounded by a water jacket, 
which maintains its proper temperature and pre¬ 
vents the valve seats being warped from over¬ 
heating, which might otherwise occur. 

When the inlet-valve is atmospherically or suc¬ 
tion operated, it is opened by the partial vacuum 
in the cylinder during the suction period, and 
closed by a spring. The inlet and exhaust-valve 
openings are usually made of such a diameter that 
the velocity of the gas as it enters the cylinder is 
about 100 feet per second, the velocity of the 
exhaust gases through the exhaust opening being 
about 80 feet per second. 

Valves, Diameter and Lift of. To ascertain 
the proper diameter of inlet and exhaust-valve 
openings and the lift of the valve to give an 
opening equal to the area of the valve opening, 
the following formulas will be found useful. 

Let B be the bore of the motor cylinder in 
inches, and S the stroke of the piston also in 
inches. As R is the number of revolutions per 
minute and D the required diameter of the valve 
opening, then 


BXSXR 



GAS AND OIL ENGINE HAND-BOOK 223 


Example: Required the diameter of the admis¬ 
sion-valve opening for a motor of 6-inch bore 
and 9-inch stroke at 600 revolutions per minute. 

Answer: As 6 multiplied by 9 and by 600 
equals 32,400, then 32,400 divided by 15,000 
gives 2.16 inches as the diameter of the valve 
opening. 

The lift of the 45-degree bevel-seat form of 
valve requires to be about three-eighths of the 
diameter of the valve opening: that is, if L is the 
required lift of the valve and D the diameter of 
the valve opening, then 

L= ^r°- 35D 

The bevel-seat form of valve is to be preferred 
to the flat-seat or mushroom type of valve, for 
two reasons: first, that it is more readily kept in 
shape by re-grinding, and second, it gives a freer 
and more direct passage for the gases. 

For an atmospherically operated admission- 
valve which will insure practically a full charge 
in the motor cylinder the formula should be 


D 


BXSXR 

12,750 


Both inlet and exhaust-valves should be of 
ample area and short lift, and be arranged sc 
that they may be readily inspected and adjusted, 
and with as few joints as possible. 



224 GAS AND OIL ENGINE HAND-BOOK 

Valve Lifters. Figure 55 illustrates a form of 
valve operating mechanism in which the valve 

is actuated by 
means of a roller 
upon the end of 
a rocker arm, to 
the upper side of 
which is secured 
a hardened steel 
plate, which in 
most cases acts 
directly upon the 
end of the valve- 
stem. 

Another form 
of valve lifter is 
shown in Fig¬ 
ure 56, in which 
the rocker arm is 
omitted, the cam 
operating the valve through the medium of a 
plunger rod and roller. 

Valve Operating Mechanism. A form of 
valve operating mechanism is shown in Fig¬ 
ure 57, in which both the inlet and exhaust- 
valves are operated independently by means 
of a rocker-shaft and lifting arms, through 
the medium of two cam-rods and levers shown 
at the right of the drawing. The lifter-arm and 
cam-rod lever of the inlet-valve are in one 



FIG. 55 

Valve lifter and roller lever with hard¬ 
ened steel lifter plate. 









GAS AND OIL ENGINE HAND-BOOK 225 


piece, and work free on the end of the rocker 
shaft. 

Valve Stems, Fit of. The inlet and exhaust- 
valve stems should not be a very close fit in their 



FIG. 56 

Valve lifter with cam acting directly on the lifter. 


guides. If the fit in these guides is made too close, 
when the valve-chamber becomes heated the con¬ 
sequent expansion may cause the valve-stem to 
stick in the guides, and leakage of the valve will 
result. 

The valve seats are in some engines left almost 
sharp, being not more than one-sixteenth of an 
inch wide before grinding. 

Valves, Timing of. The movement of the 
valves should always be timed to give the proper 
results. This is an important point to remem¬ 
ber. The cam shaft on a four-cycle engine is 








226 GAS AND OIL ENGINE HAND-BOOK 


usually driven by the two to one gear on the 
crank shaft, and if for any reason the gears are 

taken apart and 
put together, 
even if only 
one tooth out of 
place, it will 
throw the valve 
mechanism out 
of time. 

To ascertain 
if the valves of 
an engine are 
properly timed, 
turn the fly- 
wheel over 
slowly and no¬ 
tice at what 
points the valves open and close, and when* the 
ignition, if electric, takes place. 

The exhaust-valve should open when about five- 
sixths of the stroke is completed and close at the 
end of the next stroke. The next inward stroke 
is the compression stroke, when all valves should 
be closed. At the beginning of the next outward 
stroke the inlet-valve should be slightly open. 

If the engine is taken to pieces, it is important 
that a tooth of the gear wheel on the crank shaft 
and a corresponding space of the gear on the 
cam shaft should be marked, so that when put 

















GAS AND OIL ENGINE HAND-BOOK 227 


together again the same-teeth may mesh together, 
and so avoid altering the throw of the cams and 
consequent timing of the valves. 

Viscosity of Oils. The figures given for the 
viscosity of an oil denote, in seconds, the time 
taken by 1,000 grains of oil to flow through a 
small orifice in the testing apparatus at various 
temperatures. 

The standard usually adopted for viscosity is 
genuine sperm oil, which is taken as 100 at 
70 degrees Fahrenheit. 

Water Cooling System. The pipes should 
be of ample capacity, and the pipe leading from 
the top of the cylinder jacket to the upper part 
of the water tank should be arranged so as to be 
as short as possible, and any necessary bends 
should be as large as possible. 

The water supply should enter near the exhaust 
opening and leave it at the highest point of the 
cylinder jacket. 

The water required in the tank should be from 
20 to 25 gallons per horsepower, and the quantity 
required to circulate in the water jacket to keep 
the cylinder cool is about 4j gallons per horse- 
power. 

The temperature of the water from the cylinder 
jacket should never be over 140 to 160 degrees 
Fahrenheit, and if the load is constant this may 
be reduced, but be never less than 100 degrees 
Fahrenheit. 


228 GAS AND OIL ENGINE HAND-BOOK 


If the temperature of the cylinder is allowed 
to exceed 400 degrees Fahrenheit lubrication will 
be difficult, and if the cylinder jacket is found to 
be much hotter than the water in the tank, the 
water circulation is poor from scale or incrusta¬ 
tion, and should be at once attended to. 

Never run the engine without water in the 
cylinder jacket, and always keep the level of the 



Proper method of installing water-tank for thermo-syphon or 
gravity water cooling system. 

water in the tank at least six inches above the 
upper pipe. 

Figure 58 shows the proper manner of connect¬ 
ing the water tank to the cylinder jacket. The 
tank should be connected to the .engine with 



























GAS AND OIL ENGINE HAND-BOOK 229 

short lengths of rubber hose in the piping to 
prevent any joints or connections working loose 
from the engine vibration. 

The object of the water is not to keep the 
cylinder cold, but simply cool enough to prevent 
the lubricating oil from burning. The hotter the 
cylinder with effective lubrication the more power 
the engine will develop. 

It should be remembered that a hot engine is 
Ihe more economical in fuel. 

Water-jackets. The thickness of the water- 
jacket space around the cylinder of a gas nr oil 
engine should not be less than one-eighth of the 
bore of the cylinder, while the water space sur¬ 
rounding the head of the combustion chamber of 
the cylinder should not be less than one-sixth of 
the cylinder bore. 

Bosses for pipe connections to the water-jacket 
outlet should always be placed at the highest 
point of the jacket, so as to prevent an air space 
being formed above the outlet of the jacket. 
Steam will be formed in this space, and with 
a gravity or thermal-syphon system is liable 
to blow or force the water out of the cylinder 
jacket. . 

To obtain the greatest degree of fuel economy 
and engine efficiency the jacket water should be 
always of a temperature slightly under the boiling 
point of water. A cool water-jacket is a sign of 
an inefficient engine. 


230 GAS AND OIL ENGINE HAND-BOOK 


Water-jacket Circulation. Figure 59 shows 
the proper manner of making the water-jacket 



Water-circulation through the cylinder and valve chamber of a 
gas or oil engine. 

pipe connections when the cooling water is taken 
from a hydrant. 

The water from the inlet-pipe enters the 
bottom of the cylinder near the combustion 
chamber, passing around the valve chamber and 
out through the upper pipe into the funnel at the 
top of the waste pipe. A connection should be 
made into the waste pipe from the bottom of the 



























GAS AND OIL ENGINE HAND-BOOK 231 


water-jacket as shown, so as to enable the jacket 
water to be drawn off in cold weather. 

Water-jacket, Draining the. During cold 
weather always close the tank valves and open 
the drain cock so as to drain all the water from 
the water-jacket and the pipes leading from the 
water-jacket to the tank, as a freeze-up in the 
water-jacket would be sure to injure the cylinder 
jacket and possibly ruin it. It is a good rule 
during the cold weather to shut off the water 
from the cooling tank and drain the cylinder 
jacket from three to five minutes before shutting 
the engine down, thereby making sure that all 
traces of water are out of the cylinder jacket and 
pipes. Also in starting the engine in cold 
w T eather it is best not to turn on the water until 
the engine has been running from three to five 
minutes. 

Water-jacket, Testing of. The water-jackets 
of cylinders or valve-chambers should be all 
tested by air pressure to at least 120 pounds 
pressure per square inch before the piston is put 
into the cylinder. 


ADDENDUM 


Gas Engine Troubles. For those who hav* 
not the time to study gas engine principle? 
this section is included. 

Many of the troubles are due to the opera- 
tor’s ignorance of the principles of operation, 
or to negligence in taking care of the engine. 

One of the most common mistakes is trying to 
make the engine run without fuel. The opera¬ 
tor will turn the starting crank until out of breath 
when he will suddenly discover that the 
gasoline tank is empty! 

A gas engine will not run without gas, but it 
is hard to get this simple fact fixed permanently 
in the mind of the operator. 

Another trouble, similar to the empty gaso¬ 
line tank, is trying to make the engine run with¬ 
out a spark to ignite the compressed charge. 
Sometimes a connection in the wiring will break 
which will deceive the operator. 

A short circuit, in an unexpected place, will lead 
to the same trouble. 

See that the engine gets a proper charge, then 
see that the spark is heavy enough to fire it. 

Do not turn the starting crank or fly wheel 
until patience and endurance are entirely ex¬ 
pended. 


232 



GAS AND OIL ENGINE HAND-BOOK 233 


If the engine does not start promptly in four 
or five turns, the right conditions are not present 
and the operator should use a little common 
sense instead of so much muscle. Correct the 
faulty conditions and the engine will start at 
once. 

The simplicity of the causes leading to the 
above mentioned troubles is sufficient reason for 
their existence. 

Oiling a Gas Engine. The oiling of the 
engine should be done in a thorough manner. 
Use machine oil on the various parts of the en¬ 
gine, except in the cylinder. A special oil for 
gas engines should be used for the cylinders. 

Steam cylinder oil is not well adapted to a gas 
engine cylinder. A light cylinder oil, of high fire 
test, is best adapted to use in the gas engine 
cylinder. Some gas engines are fitted at the 
wrist pin and journal bearings with grease cups, 
which should be filled with shafting and set so 
as to feed automatically. 

When oil and grease cups are filled and all 
bearing parts that are liable to wear are oiled, 
the valve stems 4 should be tried by lifting the 
valve from its seat a number of times after pub 
ting some kerosene oil on the stem with an oil 
can. The stems should be frequently examined 
and kerosene oil used occasionally to keep them 
clean. Never use ordinary lubricating oil on 
them. The heat simply burns it and leaves a 


234 GAS AND OIL ENGINE HAND-BOOK 


gummy deposit on the stem which interferes with 
the free movement of the valve. 

It is said that oil is cheaper than machinery 
and we want to earnestly emphasize the truth of 
that statement. 

It should be good oil, however, for there is a 
great difference in the quality of oils, and good 
oil only can be considered if the cost of the ma¬ 
chine is kept in mind. 

Some of the so-called lubricating oils on the 
market have but little more value than so much 
water. 

It is not only a question of economy in using 
a good lubricant with an engine, but also of in¬ 
creasing the net power for effective work. 
This is especially true with the gas engine for 
it depends on the oil to make the piston and 
rings tight to hold both the compression and the 
high pressure of the explosion. 

The most accurate job of machining and fit¬ 
ting of the cylinder, piston and rings would not 
hold these pressures without a film of good gas en- 
ine oil between the piston and the cylinder walls. 

The importance of proper lubrication can 
hardly be overestimated as will be readily ap¬ 
parent when the action of a good oil, either on 
the cylinder walls or in a properly adjusted bear¬ 
ing is thoroughly understood. 

A good oil forms an almost frictionless film 
between the surfaces of the piston, rings and 


GAS AND OIL ENGINE HAND-BOOK 235 


walls of the cylinder, or between the shaft and 
the bearing as the case may be, and thus prevents 
the metals from coming in direct contact. With¬ 
out direct frictional contact there is, of course, 
no wear or deterioration of the metals so long 
as the proper condition is maintained, hence we 
must conclude that the natural wear we figure 
on in the fife of any machine is due to imperfect 
lubrication a portion of the timeo 

It is a difficult thing to maintain a perfect 
condition at all times, but the use of good oil and 
proper attention to the oiling will greatly in¬ 
crease the fife of the machine to say nothing of 
the saving of repairs, trouble and loss of time 
in repairing, etc. 

It does not follow, however, that an excessive 
amount of oil should be applied as is often done 
on the theory that if a little is good more is 
better. When too much oil is applied the sur¬ 
plus runs out of the bearing and is often wasted 
besides making a greasy, dirty engine. 

In the case of the cylinder too much oil will 
accumulate and burn in the combustion chamber, 
leaving a carbon deposit on the walls of the com¬ 
pression space besides fouling the sparking 
mechanism and causing a disagreeable smoke at 
the exhaust. 

Probably the worst possible result of a too 
liberal use of oil is the danger of the machine 
running dry between spasmodic oilings. 


236 GAS AND OIL ENGINE HAND-BOOK 


The operator, feeling sure that he has used 
plenty of oil to last a considerable length of 
time (which he has if it had been properly ap¬ 
plied) will neglect the machine and overlook the 
fact that only a limited amount of oil will be re¬ 
tained in the bearing. 

The all-important thing in perfect lubrica¬ 
tion is to supply a good oil frequently and regu¬ 
larly, or continuously if possible, to the parts 
where there would be great friction. 

Do not feel content in seeing that the oil is 
flowing, but know positively that it is going to 
the right place. 

Many fine bearings have been utterly ruined 
by the oil holes and channels becoming clogged 
so that the oil, though freely applied, could not 
reach all parts of the bearing. 

Cylinders and the more important bearings of 
the gas engine are generally oiled by pressure 
feed and sight feed oilers. 

These oiling devices should be kept in first 
class condition and set to feed the oil in the 
right quantity and regularly while the engine is 
running. 

Ordinary machine oils are of little value for 
gas engines because the fire test is entirely too 
low to stand the high heat of the cylinder and 
piston. 

Use a good gas engine oil, feeding it constantly 
or at least frequently and regularly, but do not 


GAS AND OIL ENGINE HAND-BOOK 237 


be wasteful, keep in mind the old adage revised, 
Good oil is cheaper than machinery. 

For main bearings and similar places it is very 
common to use cup grease or what is sometimes 
called “hard oil” which is fed or forced to the 
bearing by a special grease cup. 

As the bearing warms up under service the 
grease melts and produces the film, similar to 
liquid oils, to prevent wear and relieve the fric¬ 
tion. The process of converting the grease to 
an oil film, being somewhat automatic, is a good 
point for cup grease as against liquid oil for 
some kinds of service, but do not forget that the 
quality of the grease to be used is just as impor¬ 
tant as with the liquid oils. 

Timing the Spark. The timing of the spark 
is of much greater importance than was realized 
for many years after the gas engine came into use. 

Although the charge under compression fires 
easily and burns rapidly, yet it requires a small 
period of time, and the spark must occur far 
enough ahead of the end of the stroke so that 
the charge will be ignited and the expansion tak¬ 
ing place when the piston starts on its power 
stroke. If the spark occurs too late a part of 
the effective power stroke is lost, while if the 
spark occurs too early the heat expansion begins 
before the piston reaches the end of its stroke. 
This will cause the engine to pound or perhaps 
stop, if the ignition occurs very much too early. 


238 GAS AND OIL ENGINE HAND-BOOK 


The correct time for the spark depends en¬ 
tirely on the speed of the engine. At high speeds 
the spark must be advanced or made further 
ahead of the end of the stroke to give the nec¬ 
essary time for ignition, while at low speeds the 
spark may be retarded or made later. 

It is necessary to provide high speed engines 
with a device for retarding the spark when start- 
ting and changing to the advanced position 
after the engine gets up speed. 

Owing to the varying speeds used it is im¬ 
possible to give a set position for the correct 
point of ignition, but the proper timing of the 
spark may be readily determined by a little ex¬ 
perimenting with the engine under full load. 
The correct position will soon be ascertained 
by observing the results of early or late igni¬ 
tion. 

A gas engine will run with the valves and spark 
considerably out of time, but its full power and 
efficiency will not be developed unless the timing 
is right. 

Loose Flywheel. Sometimes a flywheel may 
be loose on a shaft and produce a rubbing noise 
instead of a series of thumps and pounds. This 
is often due to some part of the wheel rubbing 
against some other part of the engine or other 
article nearby. But then it may be said that it 
requires no special training to make an operator 
careful of his flywheel. 


GAS AND OIL ENGINE HAND-BOOK 239 


Pressure Leaks. There is much loss of 
power and waste of fuel from pressure leaks 
through sparker j oints and packed j oints. Many 
stationary engines are fitted with make-and- 
break mechanisms, which are designed to make 
the contact and separation of the igniter points 
within the compression space. This necessitates 
that at least one of these points be attached to a 
movable or rocker shaft extending through some 
part of the cylinder wall to the outside, to which 
an actuating device is attached. 

The very fact that this shaft requires move¬ 
ment demands either a ground shoulder or some 
other ground or packed joint to prevent the 
escape of the explosion pressure. The high ex¬ 
plosion pressure coming on at successive im¬ 
pulses is difficult to confine. 

When once the pressure finds the least avenue 
of escape, it is not long in enlarging it so that a 
large percentage of power force escapes without 
doing any effective service. 

The sparker mechanism of the make-and-break 
variety is usually attached to or mounted onto a 
plate or plug which is fitted into the sparker 
port in the cylinder walls. This plug or plate 
fits either into a ground seat or by means of a 
packed joint onto the cylinder, and in some in¬ 
stances is threaded into the cylinder walls. 

Water Jacket Temperature. The object 
of the water jacket on a gas engine cylinder is 


240 GAS AND OIL ENGINE HAND-BOOK 

to maintain the cylinder at an even temperature 
without over-heating. If the cylinder were run 
perfectly hot, the expansion of the metals would 
be such that the piston would soon stick, or 
seize, and the high temperature would consume 
the lubricating oil. To get the best results, the 
temperature of the water in the cylinder jacket 
should be as near 180 degrees as possible, but 
in the marine motor little attention is ever given 
to this. As long as the motor keeps reasonably 
cool and continues to work well, the average 
operator lets things alone. A number of motors 
have been failures owing to insufficient water- 
jacketing, and there are others which have had 
too much water-jacketing. The first means that 
the motors do not work at all, the latter, that 
they do not get the full benefit of the expansion 
of the gases and are consequently wasting 
gasoline. 

Pumps. All pumps on two-cycle motors have 
an impulse at every revolution of the crankshaft. 
This is unavoidable, but it is mechanically very 
bad practice, as the average marine motor will 
make about 500 revolutions per minute, and any 
plunger pump loses its efficiency above a speed 
of 300 strokes per minute. 

This is one reason why in practice these 
pumps give such a poor circulation. The remedy 
would be to gear the pump so that the motor 
would make about four revolutions to one of the 


GAS AND OIL ENGINE HAND-BOOK 241 


pump, and increase the size of the pump. This 
won id, however, add considerably to the cost of 
the engine. On some engines a pump of the 
rotary type is used, and while these pumps will 
deliver a perfectly steady and constant flow they 
will soon lose their efficiency if there be any sand 
or grit in the water. 

Vaporizing Valves. While these valves are 
exceedingly simple and operated entirely by the 
suction of the engine, they are capable of giv¬ 
ing a great deal of trouble. At the point where 
the gasoline is fed under the seat of the valve 
the opening is generally less than one thirty- 
second of an inch, and it very often happens 
that a small particle of foreign substance 
contained in the gasoline will settle at this 
point. 

When the valve is pressed up by hand, the gasO' 
line will apparently flow all right, but when the 
engine is started it will make but a few revo¬ 
lutions and stop for want of gasoline. The 
small particle, by the quick suction of the en¬ 
gine, will be drawn into the gasoline opening, 
shutting off the flow of gasoline, falling back 
again when the engine stops, in other words, 
acting as a check valve. This is a very common 
occurrence, and a small wire for cleaning the 
gasoline inlet should always be on hand. It 
often happens that the spring in the vaporizer 
becomes weak, and in this case it will admit of 


242 GAS AND OIL ENGINE HAND-BOOK 


an overcharge of air. To remedy this, remove 
the spring and stretch it out. In order to de¬ 
termine how much the spring has been stretched, 
it is a good plan to measure it first. 

Gasoline Pipes. A source of trouble is in 
the location of the gasoline tank. This in many 
cases has to be placed so low that if the boat is 
loaded by the head the gasoline will not flow to 
the vaporizer when the tank is nearly empty. 
A source of annoyance is the practice of running 
the gasoline pipe around under the lockers, es¬ 
pecially where the gasoline tank is low, as in 
this case the pressure of the gasoline in the tank 
is influenced by the rolling of the boat or over¬ 
loading on either side. In some cases the gaso¬ 
line is entirely shut off when the boat is out of 
trim. The gasoline pipe should in all cases be 
led down as close to the keel of the boat as 
possible. 

Regrinding Valves. The valves of a gas 
engine have to be reground in case any leakage 
occurs, for, a leak once started rapidly grows 
worse and a serious leak makes starting diffi¬ 
cult or perhaps impossible. An engine may run 
along for many months without leakage of 
valves, but it is good policy to make occasional 
tests or inspection to avoid future trouble. 

All valves made by experienced manufactur¬ 
ers are provided with a slot for a screwdriver as 
a means of rotating the valve on its seat. 


GAS AND OIL ENGINE HAND-BOOK 243 


The best material for grinding, tripoli ground, 
but as this may be hard to obtain in some 
places flour of emery may be substituted. Flour 
of emery may be purchased at any drug store, 
but it does not grind so rapidly or make as 
smooth a surface as the tripoli. 

A little lard oil is used to retain the grinding 
material between the valve and its seat. If lard 
oil is not at hand common kerosene will answer 
the purpose. Ordinary machine oil is a very 
poor substitute and should not be used if lard 
oil can possibly be obtained. 

Apply the oil and grinding material to the 
face of the valve and replace in its position in 
the guide. With a common bit brace and screw¬ 
driver blade revolve the valve on its seat until 
an even bearing is obtained. An ordinary screw 
will do if the bit brace and screw-driver blade 
are not available. 

Use a firm steady pressure on the valve while 
grinding but not too much. Lift the valve from 
its seat at short intervals to allow the oil and 
grinding material to run back over the surfaces. 
Clean the valve and seat occasionally and stop as 
soon as a full even bearing is shown. 

Restricted Exhaust or Inlet Ports. A re¬ 
stricted exhaust may retain a higher degree of 
heat in the cylinder and thereby assist in main¬ 
taining incandescent some projecting point in 
the combustion chamber. 


244 gas and oil engine hand-book 

Restricted valve ports are a hindrance to 
the development of power. The valve propor¬ 
tions should always be carefully figured from the 
piston speed and the cylinder area. 

The inlet valve area should be such as to give 
the gases a speed of from 90 to 100 feet per second. 
The exhaust gases should leave the cylinder at 
from seventy-five to eighty-five feet per second 
at atmospheric pressure. 

The exhaust valve should be larger than the 
inlet valve, because at the time of opening 
the exhaust valve there is a pressure of from 
twenty-five to thirty-five pounds in the cylin¬ 
der to relieve, and the velocity of the exhaust 
gases at the moment of release is above 100 feet 
per second, and if it had to pass through a re¬ 
stricted valve port it would maintain the initial 
high speed throughout the exhaust stroke of the 
piston, resulting in back pressure during the en¬ 
tire exhaust stroke. 

The point, then, is to figure the exhaust port 
of such proportions as to relieve the exhaust 
gases at an average speed throughout the ex¬ 
haust stroke of not over 100 feet per second. 

It is the height of folly to have a big cylinder 
port, and then choke the passage with a little 
valve or vice versa. 

The passage should be of uniform area and 
of ample capacity from the cylinder port to the 
end of the pipe. 


GAS AND OIL ENGINE HAND-BOOK 245 

Types of Gasoline Engines. When choos¬ 
ing a gasoline engine for operating a boat there 
are a number of points to be dealt with. The 
gasoline engine is expected to be in working 
order at all times and it must never break down. 
If it does, the operator will decry the gasoline en¬ 
gine, its builders and all who have anything to do 
with it. If a steam engine breaks down, there may 
be some strong words used with reference to its 
maker, but as a rule nothing is said against the 
steam engine as a prime mover, for the simple 
reason that we are accustomed to its vagaries. 

While much more is expected of the gasolin e 
engine than of the steam engine, the previous 
assertion is none the less true that reliability of 
operation is the primary consideration. Economy 
of fuel, which is a matter of first importance with 
all prime movers on land, becomes a secondary 
requirement as far as the marine gasoline engine 
is concerned, and more especially when these 
engines are to be used for small powers. It is a 
mistaken notion that anyone can operate a gaso¬ 
line engine. A child will get on very well after 
being taught, and until something happens. 
Then comes the necessity for a man with rea¬ 
soning powers that are well developed and with 
a clear head. All kinds of things may happen 
to a vessel, if its motive power gives out. A 
great many things may happen to a gasoline 
engine in indifferent hands. 


246 GAS AND OIL ENGINE HAND-BOOK 


Before going further it may be necessary to 
explain briefly the principles of operation of the 
two types used for marine purposes. These 
types are the four-cycle engine, in which there 
is but one impulse for each two revolutions of 
the crankshaft, and the two-cycle engine, in 
which an impusle occurs at each revolution of 
the crankshaft. Of the two, the four-cycle 
engine is most used for stationary purposes, but 
in marine practice the two-cycle engine is in the 
lead. Although not generally considered as eco¬ 
nomical of fuel as the four-cycle engine, it can 
be built much lighter for the same power, and 
the great frequency of the impulses makes it 
much steadier in operation. This can perhaps 
be realized better when it is remembered that 
a single cylinder steam engine receives an im¬ 
pulse at every stroke of the piston, or two im¬ 
pulses at every revolution of the crankshaft, 
while the four-cycle gasoline engine receives but 
one impulse to two revolutions, or one impulse 
to four in the steam engine. The steam engine 
also receives two impulses during the same time 
that the two-cycle engine receives one. 

Multiple-Cylinder Engines. Multiple-cylinder 
engines of the two-cycle type have until quite 
recently been constructed by adding succes¬ 
sively separate engines. While these in a great 
many cases have given satisfaction, they 
have not as a whole been satisfactory. The 




GAS AND OIL ENGINE HAND-BOOK 247 


cidef trouble being that when operated by one 
carbureter, they have been inclined to flood in 
the after-cylinders. The gasoline gas being of 
greater specific gravity than air, has a tendency 
to go to the lowest point, which in the majority 
of boats would be the after-cylinders. The dis¬ 
tance apart of the separate engines also tending 
to condense the vaporized gasoline, flooding the 
crank bases of the engines with the consequence 
that no two of the cylinders have a uniform mix¬ 
ture of gas, and in many cases the after cylin¬ 
ders refuse to work at all. In order to avoid 
these difficulties, many multiple-cylinder engines 
have separate carbureters for each crank case. 
While this is all right in theory it is not good 
practice, as it is difficult to obtain the correct 
regulation of each cylinder when they are all in 
operation. There have been placed on the mar¬ 
ket a number of multiple-cylinder engines with 
the cylinders in one integral casting and sur¬ 
rounded by one water-jacket. By this means 
the cylinders are brought very close together, us¬ 
ing one carbureter, the connections from it to 
the engines by this plan are very short and 
compact. These engines in their very best form 
are not adapted to be operated by a novice. 
Owing to their high speed and the number of 
moving parts, it is very difficult to detect and 
locate troubles of any kind, and determine in 
which cylinder the trouble exists. The four-cycle 


248 GAS AND OIL ENGINE HAND-BOOK 


multiple-cylinder engine is an entirely differ¬ 
ent proposition, and especially, the double cylin¬ 
der, which is very successful. The two-cylindei 
four-cycle engine produces the same results and 
only has the same number of movements as in 
the single-cylinder two-cycle, therefore a four¬ 
cycle four-cylinder is equivalent to a two-cylin¬ 
der two-cycle engine. One of the principal 
troubles of the multiple-cylinder high speed 
engine is the ignition, as they are very hard on 
generators and batteries. 

Selecting a Boat Engine. The thing for 
the prospective purchaser to do is naturally 
to write to different makers of gasoline engines 
and obtain their catalogues and price lists. It 
will be found that each one is building the best 
engine on earth, if his story is to be believed. 
It is a sad truth, indeed, that there are many 
poor gasoline engines offered for sale in the open 
market. Several catalogues will probably con¬ 
tain an engine very nearly the size which has 
been selected for the new boat. If the catalogues 
received contain testimonials from persons who 
live in the vicinity, make it a point to call on 
them, and have a private talk with them about 
their engines. 

Find out how much the engine has been run, 
and obtain a narrative of all experiences with 
the engine when running. Find out the longest 
as well as the shortest period of time it has taken to 


GAS AND OIL ENGINE HAND-BOOK 249 



get the engine started, and how long it has been run 
at any one time without stopping. Find out if 
the engine is addicted to thumping or pounding 
in any part of the mechanism, and whether such 


FIG. 60 

Single-cylinder, two-cycle Marine Motor. 

a condition is of frequent occurrence, or only oc¬ 
casional, and also how long the ignition appa¬ 
ratus will last. If it be found that the engine 
transmits very little vibration to the boat, it may 
be presumed that the engine is well balanced. 


250 GAS AND OIL ENGINE HAND-BOOK 


Another way to tell whether an engine is in 
good balance is to see if it will run for quite a 
little time after the ignition current has been cut off. 
Of two engines, that are of the same size, and 
equally well lubricated, and which have the same 
friction resistance, the engine will run the longer 
after power is shut off that is the better bal¬ 
anced. When resting the hand upon the cylin¬ 
der head while the engine is running idle, if a 
knock is perceptible it is. a certain sign that it is 
out of balance. 

If the engine is counterbalanced in the fly¬ 
wheel instead of on the crank jaws it gives a 
twisting movement to the shaft, and the balanc¬ 
ing is imperfect. A well-balanced engine should 
have the counter-weight as nearly opposite the 
the crank pin as it is possible to place it. In 
a two-cylinder engine with the crank pins at 180 
degrees, or in a three-cylinder engine with the 
cranks at 120 degrees, a balancing effect is ob¬ 
tained which is much better than that produced 
by a counter-weight. It is the custom with 
some builders to put the crank pins on the same 
side of the shaft for a two-cylinder engine, for 
the reason that the impulses are better distributed. 
It is generally admitted that a better mechan¬ 
ical balance is obtained with the crank pins 
at 180 degrees and in a vertical two-cylinder 
engine of the four-cycle type with an enclosed 
crank case, the latter arrangement avoids the 


GAS AND OIL ENGINE HAND-BOOK 251 


pumping action that occurs when the cranks are 
on the same side of the shaft. 

If the counter-weight be in the flywheel, see 
if it has any side motion when the engine is run¬ 
ning, or, in other words, see if the flywheel is 
out of true sideways. If such is the case, it 
shows that the crank shaft is too weak for an 
engine of this kind. 

Find out if the bearings give trouble from over 
heating, and be particular to ask for any ex¬ 
perience in this matter. Find out if it is nec¬ 
essary to watch the engine at all times, or 
whether you may be secure in giving the 
engine only an occasional glance to see if it 
is running all right. 

Handling Marine Engine with Reverse 
Lever. In handling the engine when desiring to 
make a stop, no matter whether equipped with 
reversing gear or reversing propeller, never stop 
the engine until the actual stopping point is 
reached. Many accidents are caused by opera¬ 
tors getting excited and stopping the motor when 
it should have been allowed to run and depend 
on the reversing mechanism. When the engine 
has no reversing device and is dependent upon 
reversing the engine, always make the approach 
to a landing from the side. 

Propellers for Motor Boats. The propel¬ 
ler wheels used on motor boats are, as a rule, 
smaller in diameter than employed in steam 


252 GAS AND OIL ENGINE HAND-BOOK 


practice, the reason for this being that the gaso¬ 
line engine is usually run at a higher rate of 
speed, and where no reversing gear is used, the 
engine has to start against the full load of the 



FIG. 61 

Two-cylinder, two-cycle Marine Motor. 


wheel. Of late, the manufacturers have been 
using wheels of larger diameter and less pitch, 
the effect of this being to increase the efficiency 
of the propeller, making the engine easier to 
start, decreasing the number of revolutions some- 




GAS AND OIL ENGINE HAND-BOOK 253 


what, but adding to the speed of the boat. In 
order to avoid the use of the reversing gears in¬ 
side the boat, the reversing propeller is used to 
a large extent. These wheels, although of many 
different patterns, are all practically of the same 
principle, the blades being turned by the move¬ 
ment of a sleeve surrounding the propeller shaft, 
which revolves with the shaft. There are no gears 
to intermesh or any necessity for slowing down 
as with the inside reversing mechanism. These 
propellers will reverse at full speed as they al¬ 
ways travel in the same direction, they take hold 
of the water instantly. 

The reversing propeller is necessarily some¬ 
what weak structurally. It being impossible, 
for mechanical reasons, to design it as a per¬ 
fectly true screw. It therefore lacks the effi¬ 
ciency of a solid propeller. 

The word pitch, as applied to the propeller 
wheel, refers to it in the same sense as to the 
pitch of a screw, as the propeller in action should 
be a perfect screw. The pitch of the propeller 
designates the number of feet that it would 
travel in one revolution, supposing it to be a 
screw. If a propeller wheel is 20 inches in diam¬ 
eter and has 30 inches pitch, it denotes that it 
will travel 30 inches in each revolution. It is by 
this means that calculations are made on the 
speed of the boat. In small motor boats any esti¬ 
mates based on these calculations will, as a rule. 


254 GAS AND OIL ENGINE HAND-BOOK 


prove anything but reliable, as the proportion 
of beam to length is in all cases excessive in 
comparison with larger vessels. Of course, as 
the pitch of the propeller wheel is decreased, a 
slower screw is had and consequently a more 
powerful one. For this reason it is becoming 
the practice of high speed boats to use a wheel 
of the least possible pitch, and in order to gain 
on the travel of the screw to increase the num¬ 
ber of the revolutions of the propeller. 

The form and general design of the propeller 
have been so extensively experimented with, 
that the subject is almost worn threadbare, and 
it is sufficient to say that the true screw propel¬ 
ler will, in all probability, remain as at first the 
standard of excellence. 

Couplings and Thrust Bearings. On the 

opposite end of the crank shaft from the fly¬ 
wheel, is the shaft coupling and thrust bearing. 
The thrust bearing, which is intended to take 
up the thrust or push from the propeller, is 
sometimes made up of a number of balls fitted 
in a cage between the couplings and the after 
bearing of the engine, or in a great many cases 
a groove is turned in the coupling for a ball race, 
the oposite side being a flat, hardened steel 
washer. While this is a very neat and effect¬ 
ive arrangement, it has been found from actual 
experience that ball-bearings in marine work are 
not a success. The older method, and the one 


GAS AND OIL ENGINE HAND-BOOK 255 


still used on large marine engines, is the ring 
thrust, composed of a shaft with a number of 
collars turned on it which mesh into a set of 
babbitt metal rings fastened to the keel and 
entirely separate from the engine. The neces¬ 
sity of a good thrust bearing, is sadly neglected 
by the launch owner, as a thrust bearing of 
good design, if carefully looked after, will in the 
majority of cases not only keep the engine in 
much better working order and save a good deal 
of wear, but in many cases prevent a broken 
connecting rod. 

Gas Engine Design. The builders of gas 
engines have brought out a great number of dif¬ 
ferent designs in construction. 

Out of all this there have been evolved certain 
constructions that have come to be recognized 
as standard and followed by most builders. 

Cylinders are built in either a vertical or hori¬ 
zontal position. 

The principal claims for the vertical con¬ 
struction are: 

Minimum floor space occupied, impulses de¬ 
livered in the line of the foundation, thus les¬ 
sening the vibration. Less wear on the piston 
and cylinder by supporting the weight of the 
piston on the connecting rod instead of allow¬ 
ing it to lie on one side in the cylinder. 

These advantages are met by claims for a 
horizontal construction in that better lubrica- 


256 GAS AND OIL ENGINE HAND-BOOK 


tion of the .piston and cylinder walls is obtained 
by feeding the oil on top of the piston, so that 
it will flow by gravity to all parts of the wear¬ 
ing surface. 

As both constructions are in demand and both 
give excellent results in practical use, it becomes 
a matter of taste with the purchaser, and many 
manufacturers settle the question by building 
both the vertical and horizontal types. 

In most gas engines the connecting rod is 
attached directly to the piston thus eliminating 
the heavy crosshead and piston rod peculiar to 
the steam engine. As the mass or weight of 
reciprocating parts is thus greatly reduced the 
gas engine thereby approaches the ideal engine. 

A point in late design is the tendency to mul¬ 
tiple-cylinder construction, using two, three, four 
and sometimes six cylinders. Such construc¬ 
tions are much more expensive to build, but the 
important advantages of less weight for a given 
power, constant torque or turning movement, less 
vibration due to better balance and the increased 
chances against complete disability are bringing 
multiple-cylinder engines into general favor. 

In an engine with two or more cylinders the 
principle of operation for each cylinder is the 
same as for a single-cylinder engine. The cylin¬ 
ders are, however, made to deliver their impulses 
one after the other, the time between the im¬ 
pulses being made as nearly equal as possible. 


GAS AND OIL ENGINE HAND-BOOK 257 


TABLES 


Density and Specific Gravity Equivalents. 


| Baume 

l 

Specific Gravity 

Baume 

Specific Gravity 

Baume 

Specific Gravity 

10° 

1.0000 

37° 

0.8395 

64° 

.7423 

11° 

0.9930 

38° 

.8346 

65° 

.7205 

12° 

.9861 

39° 

.8299 

60° 

.7168 

13°“ 

.9791 

40° 

.8251 

67° 

.7133 

14° 

.9722 

41° 

.8204 

68° 

.7097 

15° 

..9058 

42° 

.8457 

69° 

.7061 

10° 

.9594 

43° 

.8110 

70° 

.7025 

17° 

.9530 

44° 

.8063 

71° 

.6990 

' 18° 

.9460 

45° 

.8017 

72° 

.6956 

f 19° 

.9402 

40° 

.7971 

73° 

.6923 

| 20° 

.9339 

47° 

.7927 

74° 

.6889 

i 21** 

.9280 

48° 

.7883 

75° 

.6856 

22° 

.9222 

49° 

.7838 

76° 

.6823 

| 23° 

.9103 

50° 

.7794 

77° 

.0789 

! 24° 

.9105 

51° 

.7752 

78° 

.6756 

1 25° 

.9047 

52° 

.7711 

79° 

.6722 

26° 

.8989 

53° 

.7670 

80° 

.6689 

1 27° 

.8930 

54° 

.7628 

81° 

.6650 

i 28° 

.8872 

55° 

.7587 

82° 

.6619 

1 29° 

.8814 

56° 

.7546 

83° 

.65S3 

30° 

.8755 

57° 

.7508 

84° 

.6547 

31° 

.8702 

58° 

.7470 

85° 

.6511 

32° 

.8650 

50° 

.7432 

86° 

.6481 

33° 

.8597 

C0° 

.7394 

87° 

.6151 

34° 

.8544 

61° 

.7357 

88° 

.6422 

35° 

.8492 

62° 

.7319 

89° 

.6392 

36° 

.8443 

63° 

.7281 

90° 

.6363 


The scale generally used for indicating the densities 
of liquids is that of Baume. Zero on this scale corre¬ 
sponds to the density of a solution of salt of specified 
proportions, and 10 degrees corresponds to the density 
of distilled water at a specified temperature or to. a 
specific gravity of unity. The portion of the stem of 
the instrument lying between these two points is di¬ 
vided into ten equal parts and the rest of the stem is 
divided into divisions of equal size up to 90 degrees. 
Higher numbers indicate lower specific gravities. The 
above table shows the relation existing between the 
Baum6 scale and specific gravity proper. 















258 GAS AND OIL ENGINE HAND-BOOK 


Dimensions of Machine Screws. 


Number of 
Screw. 

Threads per 
Inch. 

Diameter of 
Body. 

Diameter at 
Bottom of 

Thread. 

No. of Tap Drill 

for Full Thread. 

No. of Drill for 

Body. 

Flat Head. 2 

p 

a 

.eter of 

a 

S'd 

p ® 

ma 

Head. 

u 

S 

GG • 

a a 

S o3 

£a 

2 

56 

.084 

.053 

54 

44 

.16 

.15 

.13 

4 

36 

.110 

.062 

52 

34 

.22 

.20 

.17 

6 

32 

.136 

.082 

45 

28 

.27 

.25 

.22 

8 

32 

.163 

.109 

35 

19 

.32 

.29 

.26 

10 

32 

.189 

.135 

29 

11 

.37 

.35 

.30 

12 

24 

.216 

.144 

27 

2 

.43 

.39 

.34 

14 

20 

.242 

.156 

22 

i 

.48 

.44 

.39 

16 

20 

.268 

.182 

14 

A 

.53 

.49 

.43 

18 

18 

.294 

.198 

8 

if 

.58 

.52 

.47 


Safe Working Load of Steel Balls. 


Diameter of ball. 

i 

A 

* 

iV 

i 

A 

f 

Working load per 
ball in pounds . . 

500 

780 

1125 

1530 

2000 

2530 

3125 


Composition of Alloys. 



3 

E-t 

Copper. 

Zinc. 

Antimony 

Lead. 

Bismuth. 

Bronze, for Engine bearings .. 
Brass, for light work, other 
than bearings. 

13 

110 

1 




2 

1 




Bronze flanges, to stand braz¬ 
ing . 


32 

1 


1 


Genuine Babbitt metal. 

10 

1 


i 



Bronze, for bushings. 

Metal, to expand in cooling for 
patterns . 

16 

130 

i 

2 

9 

1 

Genuine bronze. 

2 

90 

5 


2 


Spelter, hard. 


1 

1 




Spelter, soft. 

1 

4 

3 































































GAS AND OIL ENGINE HAND-BOOK 259 


Strength and Weight of Materials. 


Material. 

Tensile 

Strength in 

pounds per 

square inch. 

Resistance 

to Compres¬ 

sion. 

Weight per 

cubic inch. 

Weight per 

cubic foot. 

Aluminum 

12,000 


.094 

162 

Brass—Cast. 

18,000 

10,000 

.290 

504 

Sheet. 

23,000 

12,500 

.295 

510 

Bronze—Aluminum. 

60,000 

12,000 

.290 

500 

Pnosphor . . 

63,000 

12,000 

.300 

530 

Copper-Cast. 

18,000 

30,000 

.313 

542 

Sheet. 

30,000 

40,000 

.317 

548 

Wire. 

50,000 


.317 

5iS 

Gun Metal . 

36,000 

15,000 

.290 

504 

Iron—Cast. 

16,000 

100,000 

.260 

450 

Malleable . . . 

18,000 

80,000 

.267 

460 

Wrought. . . . 

50,000 

36,000 

.280 

480 

Lead. 

33,000 


.410 

711 

Steel—Tool. 

100,000 

40,000 

.284 

490 

Cr. Cast. 

63,000 

36,000 

284 

490 

Mild. 

60,000 

36,000 

.284 

490 

C. Rolled .... 

63,000 

40,000 

.284 

490 


Dimensions of Involute Tooth Spur Gears. 


Diametrical 

Pitch. 

Circular 

Pitch. 

Width of 
Tooth on 
Pitch 
Line. 

Working 
Depth of 
Tooth. 

| Actual 
Depth of 
Tooth. 

Clear¬ 
ance at 
Bottom 
of Tooth. 

1 

3.142 

1.571 

2.000 

2.157 

0.157 

2 

1.571 

0.785 

1.000 

1.078 

0.078 

3 

1.047 

0.524 

0.667 

0.719 

0.052 

4 

0.785 

0.393 

0.500 

0.539 

0.039 

5 

0.628 

0.314 

0.400 

0.431 

0.031 

6 

0.524 

0.262 

0.333 

0.360 

0.026 

7 

0.447 

0.224 

0.286 

0.308 

0.022 

8 

0.393 

0.196 

0.250 

0.270 

0.019 

10 

0.314 

0.157 

0.200 

0.216 

0.016 

12 

0.262 

0.131 

0.167 

0.180 

. 0.013 

14 

0.224 

0.112 

0.143 

0.154 

0.011 

16 

0.196 

0.098 

0.125 

0.135 

0.009 


































260 GAS AND OIL ENGINE HAND-BOOK 


Melting Point of Metals. 


Metal. 

Temperature 

in Degrees 

Fahrenheit. 

Metal. 

Temperature 

in Degrees 

Fahrenheit. 

Aluminum. 

1160° 

1690° 

1930° 

1900° 

2000° 

3000° 

Lead. 

620° 

3230° 

1730° 

2400° 

445° 

780° 

Bronze. 

Platinum . 

Silver. 

Copper. 

Gold. 

Steel. 

Iron—Cast. 

Tin. 

Wrought . 

Zinc . . .•. 


Weight per Cub*c Foot of Substances. 


Materials. 

Weight 

in 

Pounds. 

Ash, White. 

38 

Asphaltum ...... 

87 

Brick—Pressed. . . 

150 

Common. . 

125 

Cement—Louisville 

50 

Portland 

90 

Cherry. 

42 

Chestnut. 

41 

Clay, Potter’s 

110 

Coal—Anthracite. 

93 

Bituminous 

84 

Earth. 

95 

Ebony . 

76 

Elm. 

35 

Flint. 

162 

Gold, Pure. 

1204 

Hemlock. 

25 

Hickory. 

53 

Ivory . 

114 

Lignum Vitae. 

83 

Magnesium ...... 

109 

Mahogany. 

53 

Maple. 

49 

Marble. 

168 


Materials. 

Weight 

in 

Pounds 

Mercury. 

849 

Mica. 

183 

Oak, White.. 

50 

Petroleum. 

55 

Pine—White .... 

25 

Northern. . 

34 

Southern. . 

45 

Platinum. 

1342 

Quartz. 

165 

Resin.. 

69 

Sand—Dry. 

98 

Wet. 

140 

Sandstone. 

151 

Shale. 

162 

Silver. 

655 

Slate. 

175 

Spruce. 

25 

Sulphur. 

125 

Svcamore . 

37 

Tar. 

62 

Peat.. 

26 

Walnut, Black . . . 

38 

Water—Distilled . 

62* 

Sea. 

64 
































































GAS AND OIL ENGINE HAND-BOOK 261 


Squares and Square Roots of Numbers from 1 to 100. 


! 

Nos. 

Squares. 

Square 

Root. 

Nos. 

Squares. 

Square 

Root. 

1 

1 

1.000 

51 

2601 

7.141 

2 

4 

1.414 

52 

2704 

7.211 

3 

9 

1.732 

53 

2809 

7.280 

4 

16 

2.000 

54 

2916 

7.349 

5 

25 

2.236 

55 

3025 

7.416 

6 

36 

2.449 

56 

3136 

7.483 

7 

49 

2.646 

I 57 

3249 

7.550 

8 

64 

2.8’<i8 

i 58 

3364 

7.616 

9 

81 

3.000 

1 59 

8481 

7.681 

10 

100 

3.162 

60 

3600 

7.746 

11 

121 

3.317 

61 

3721 

7.810 

12 

144 

3.464 

1 62 

3844 

7.874 

13 

169 

3.606 

63 

3969 

7.9*7 

14 

196 

3.742 

64 

4096 

8.000 

15 

225 

3.873 

65 

4225 

8.062 

16 

256 

4.000 

66 

4356 

8.124 

17 

289 

4.1*3 

67 

4489 

8.185 

18 

324 

4.243 

68 

4624 

8.246 

19 

361 

4.359 

69 

4761 

8.307 

20 

400 

4.472 

70 

4900 

8.367 

21 

441 

4.583 

71 

5041 

8.426 

22 

484 

4.690 

72 

5184 

8.485 

23 

529 

4.796 

73 

5329 

8.544 

24 

576 

4.899 

74 

5476 

8.602 

25 

625 

5.000 

75 

5625 

8.660 

26 

676 

5.099 

76 

5776 

8.718 

27 

729 

5.196 

77 

5929 

8.775 

28 

784 

5.292 

78 

6084 

8.832 

29 

841 

5.385 

79 

6241 

8.888 

30 

900 

5.477 

80 

6400 

9.944 

31 

961 

5.568 

81 

6561 

9.000 

32 

1024 

5.657 

82 

6724 

9.055 

33 

1089 

5.745 

83 

6889 

9.110 

34 

1156 

5.831 

84 

7056 

9.165 

35 

1225 

5.916 

85 ' 

7225 

9.220 

36 

1296 

6.000 

86 

7396 

9.274 

37 

1369 

6.033 

87 

7569 

9.327 

38 

1444 

6.164 

88 

7744 

9.381 

39 

1521 

6.245 

89 

7921 

9.434 

40 

1600 

6.325 

90 

8100 

9.487 

41 

1681 

6.403 

91 

8281 

9.539 

■a 

1764 

6.481 

92 

8464 

9.592 

43 

1849 

6.557 

93 

8649 

9.644 

44 

1936 

6.633 

94 

8836 

9.695 

45 

2025 

6.708 

95 

9025 

9.747 

46 

2116 

6.782 

96 

9216 

9.798 

47 

2209 

6.856 

97 

9409 

9.849 

48 

2304 

6.928 

98 

9604 

9.900 

49 

2401 

7.000 

99 

9801 

9.950 

50 

2500 

7.071 

100 

10000 

10.000 
















262 GAS AND OIL ENGINE HAND-BOOK 


Areas and Circumferences of Circles from 0.05 to 
8.80, Advancing by ^ of one inch. 


Diam. 

Area. 

Circum. 

Diam. 

Area. 

i 

Circum. 

.05 

.0019 

.16 

2.15 

3.63 

6.75 

.10 

.0078 

.31 

2.20 

3.80 

6.91 

.15 

.017 

.47 

2.25 

3.98 

7.07 

.20 

.031 

.63 

2.30 

4.15 

7.22 

.25 

.049 

.78 

2.35 

4.34 

7.38 

.30 

.070 

.94 

2.40 

4.52 

7.54 

.35 

.096 

1.09 

2.45 

4.71 

7.69 

.40 

.12 

1.26 

2.50 

4.91 

7.85 

.45 

.16 

1.41 

2.55 

5.11 

8.01 

.50 

.19 

1.57 

2.60 

5.31 

8.17 

.55 

.24 

1.73 

2.65 

5.56 

8.32 

.60 

.28 

1.88 

2.70 

5.72 

8.48 

.65 

.33 

2.04 

2.75 

5.94 

8.64 

.70 

.38 

2.19 

2.80 

6.16 

8.79 

.75 

.44 

2.36 

2.85 

6.38 

8.95 

.80 

.50 

2.51 

2.90 

6.60 

9.11 

.85 

.57 

2.67 

2.95 

6.83 

9.27 

.90 

.64 

2.83 

3.00 

7.07 

9.42 

.95 

.71 

2.98 

3.05 

7.31 

9.58 

1.00 

.78 

3.14 

3.10 

7.55 

9.74 

1.05 

.86 

3.29 

3.15 

7.79 

9.89 

1.10 

.95 

3.46 

3.20 

8.04 

10.05 

1.15 

1.03 

3.61 

3.25 

8.29 

10.21 

1.20 

1.13 

3.77 

3.30 

8.55 

10.37 

1.25 

1.23 

3.93 

3.35 

8.81 

10.52 

1.30 

1.33 

4.08 

3.40 

9.08 

10.68 

1.35 

1.43 

4.24 

3.45 

9.35 

10.84 

1.40 

1.54 

4.39 

3.50 

9.62 

10.99 

1.45 

1.65 

4.56 

3.55 

9.89 

11.15 

1.50 

1.77 

4.71 

3.60 

10.18 

11.31 

1.55 

1.89 

4.87 

3.65 

10.46 

11.47 

1.60 

2.01 

5.03 

3.70 

10.75 

11.62 

1.65 

2.14 

5.18 

3.75 

11.04 

11.78 

1.70 

2.27 

5.34 

3.80 

11.34 

11.94 

1.75 

2.40 

5.49 

3.85 

11.64 

12.09 

1.80 

2.54 

5.65 

3.90 

11.94 

12.25 

1.85 

2.69 

5.81 

3.95 

12.25 

12.41 

1.90 

2.84 

5.97 

4.00 

12.57 

12.57 

1.95 

2.99 

6.13 

4.05 

12.88 

12.72 

2.00 

3.1.4 

6.28 

4.10 

13.20 

12.88 

2.05 

3.30 

6.44 

4.15 

13.53 

13.04 

2.10 

3.46 

6.59 

4.20 

I 

13.85 

13.19 













GAS AND OIL ENGINE HAND-BOOK 263 


— 

Diam. 

Area. 

Circum. j| 

Diam. 

Area. 

Circum. 

4. 

25 

14. 

19 

13. 

35 

6. 

45 

32. 

67 

20. 

26 

4. 

30 

14. 

52 

13. 

51 

6. 

50 

33. 

1.8 

20. 

42 

4. 

35 

14. 

86 

13. 

66 

6. 

55 

33. 

69 

20. 

58 

4. 

40 

15. 

20 

13. 

82 

6. 

60 

34. 

21 

20. 

73 

4. 

45 

15. 

55 

13. 

98 

6. 

65 

34. 

73 

20. 

89 

4. 

50 

15. 

90 

14. 

14 

6. 

70 

35. 

26 

21. 

05 

4. 

55 

16. 

25 

14. 

29 

6. 

75 

35. 

78 

21. 

20 

4. 

60 

16 

62 

14. 

45 

6. 

80 

36. 

32 

21. 

36 

4. 

65 

16 

98 

14 

61 

6. 

85 

36. 

85 

21. 

52 

4. 

70 

17 

35 

14 

76 

6. 

90 

37. 

39 

21. 

68 

4 

75 

17 

73 

14 

92 

6. 

95 

37. 

94 

21. 

83 

4 

80 

18 

09 

15 

08 

7. 

00 

38. 

48 

21. 

99 

4 

85 

18 

47 

15 

24 

7. 

05 

39. 

04 

22. 

15 

4 

90 

18 

86 

15 

39 

7. 

10 

39. 

59 

22. 

30 

4 

95 

19 

24 

15 

55 

7. 

15 

40. 

15 

22. 

46 

5 

00 

19 

63 

15 

71 

7. 

20 

40. 

71 

22. 

62 

5 

05 

20 

03 

15 

86 

7. 

,25 

41. 

,28 

22. 

78 

5 

10 

20 

43 

16 

02 

7. 

.30 

41, 

.85 

22. 

93 

5 

.15 

20 

.84 

16 

.18 

7. 

.35 

42, 

.43 

23. 

C9 

5 

.20 

21 

.23 

16 

.34 

7, 

.40 

43 

.01 

23. 

25 

5 

.25 

21 

.65 

16 

.49 

7. 

.45 

43 

.59 

23. 

.40 

5 

.30 

22 

.06 

16 

.65 

7 

.50 

44 

.18 

23 

.56 

5 

.35 

22 

.48 

16 

.81 

7 

.55 

44 

.77 

23 

,72 

5 

.40 

22 

.90 

16 

.96 

7 

.60 

45 

.36 

23 

.88 

5 

.45 

23 

.33 

17 

.12 

7 

.65 

45 

.96 

24 

.03 

5 

.50 

23 

.76 

17 

.28 

7 

.70 

46 

.57 

24 

.19 

5 

.55 

24 

.19 

17 

.44 

7 

.75 

47 

.17 

24 

.35 

5 

.60 

24 

.63 

17 

.59 

7 

.80 

47 

.78 

24 

.50 

5 

. 65 

25 

.07 

17 

.75 

7 

.85 

48 

.39 

24 

.66 

5 

.70 

25 

.52 

17 

.91 

7 

.90 

49 

.02 

24 

.82 

5 

.75 

25 

.97 

18 

.06 

7 

.95 

49 

.64 

24 

.97 

5 

.80 

26 

.42 

18 

.22 

8 

.00 

50 

.26 

25 

.13 

5 

.85 

26 

.88 

.18 

.38 

8 

.05 

50 

.89 

25 

.29 

5 

.90 

27 

.34 

18 

.54 

8 

.10 

51 

.53 

25 

.43 

5 

.95 

27 

.80 

18 

.69 

.8 

.15 

52 

.17 

25 

.60 

6 

.00 

28 

.27 

18 

.85 

: 8 

.20 

52 

.81 

25 

.76 

6 

.05 

28 

.75 

19 

.01 

8 

.25 

53 

.46 

25 

.92 

6 

.10 

29 

.22 

19 

.16 

8 

.30 

54 

.11 

26 

.07 

6 

.15 

29 

.70 

19 

.32 

8 

.35 

54 

. 76 

26 

.23 

6 

.20 

30 

.19 

19 

.48 

8 

.40 

55 

.42 

26 

.39 

6 

.25 

30 

.68 

19 

.63 

8 

.45 

56 

.08 

26 

.55 

6 

.30 

31 

.17 

19 

.79 

8 

.50 

56 

.74 

26 

.70 

6 

.35 

31 

.67 

19 

.95 

8 

.75 

60 

.13 

27 

.49 

6 

.40 

32 

.17 

20 

.11 

8 

.80 

60 

.82 

27 

.65 






















264 GAS AND OIL ENGINE HAND-BOOK 


Circumferences of Circles from 0.01 to 80.9 
Advancing by IOths. 


s 

«3 

5 

.0 

.1 

.2 

.3 

.4 

.5 

.6 

.7 

.8 

.9 

j Diam. 

0 

.00 

.31 

.62 

.94 

1.25 

1.57 

1.88 

2.19 

2.51 

2.82 

0 

l 

3.14 

3.45 

3.77 

4.08 

4.39 

4.71 

5.02 

5.34 

5.65 

5.96 

1 

2 

6.28 

6.59 

6.91 

7.22 

7.53 

7.85 

8.16 

8.48 

8.79 

9.11 

2 

3 

9.42 

9.74 

10.05 

10.36 

10.68 

10.99 

11.30 

11.62 

11.93 

12.25 

3 

4 

12.56 

12.88 

13.19 

13.50 

13.82 

14.13 

14.45 

14.76 

15.08 

15.39 

4 

5 

15.70 

16.02 

16.33 

16.65 

16.96 

17.27 

17.59 

17.90 

18.22 

18.53 

5 

6 

18.84 

19.16 

19.47 

19.79 

20.10 

20.42 

20.73 

21.04 

21.36 

21.67 

6 

7 

21.99 

22.30 

22.61 

22.93 

23.24 

23.56 

23.87 

24.19 

24.50 

24.81 

7 

8 

25.13 

25.44 

25.76 

26.07 

26.3S 

26.70 

27.01 

2".33 

27.64 

27.96 

8 

9 

28.27 

28.58 28.90 

29.21 

29.53 

29.34 

30.15 

30.47 

30.78 

31.10 

9 

10 

31.41 

31.73 

32.04 

32.35 

32.67 

32.98 

33.30 

33.61 

33.92 

34.24 

10 

11 

34.55 

34.87 

35.18 

35.50 

35.81 

36.12 

36.44 

36.75 

37.07 

37.38 

11 

12 

37.69 

38.01 

38.32 

38.64 

38.95 

39.27 

39.58 

39.89 

40.21 

40.52 

12 

13 

40.84 

41.15 

41.46 

41.78 

42.09 

42.41 

42.72 

43.03 

43.35 

43.66 

13 

14 

43.98 

44.29 

44.61 

44.92 

45.23 

45.55 

45.86 

46.18 

46.49 

46.80 

14 

15 

47.12 

47.43 

47.75 

48.06 

48.38 

48.69 

49.00 

49.32 

49.63 

49.95 

15 

16 

50.26 

50.57 

50.89 

51.20 

51.52 

51.83 

52.15 

52.46 

52.78 

53.09 

16 

17 

53.40 

53.72 

54.03 

54.35 

54.65 

54.97 

55.29 

55.60 

55.92 

56.23 

17 

18 

56.54 

56.86 

57.17 

57.49 

57.80 

58.11 

58.43 

58.74 

59.06 

59.37 

18 

19 

59.69 

60.00 

60.31 

60.63 

60.94 

61.26 

61.57 

61.88 

62.20 

62.51 

19 

20 

62.83 

63.14 

63.46 

63.77 

64,08 

64.40 

64.71 

65.03 

65.34 

65.65 

20 

12 

65.97 

66.28 

66.60 

66.91 

67.22 

67.54 

67.85 

68.17 

68.48 

68.80 

21 

22 

69.11 

69.42 

69.74 

70.05 

70.37 

70.08 

71.00 

71.31 

71.62 

71.94 

22 

23 

72.25 

72.57 

72.88 

73.19 

73.51 

73.82 

74.14 

74.45 

74.76 

75.08 

23 

24 

75.39 

75.71 

76.02 

76.34 

76.65 

76.90 

77.28 

77.59 

77.91 

78.22 

24 

25 

78.54 

78.85 

79.16 

79.48 

79.79 

80.11 

80.42 

80.73 

81.05 

81.36 

25 

26 

81.68 

81.99 

82.30 

82.62 

82.93 

83.25 

83.56 

83.88 

84.19 

84.50 

26 

27 

84.82 

85.13 

85.45 

85.76 

86.07 

86.39 

86.70 

87.02 

87.33 

87.65 

27 

28 

87.96 

88.27 

88.59 

88.90 

89.22 

89.53 

89.84 

90.16 

90.47 

90.79 

28 

29 

91.10 

91.42 

91.73 

92.04 

92.36 

92.67 

92.99 

93.30 

93.01 

93.93 

29 

30 

94.24 

94.56 

94.87 

95.19 

95.50 

95.81 

96.13 

96.44 

96.76 

97.07 

30 

31 

97.38 

97.70 

98.01 

98.33 

98.64 

9S.96 

99.27 

99.58 

99.90 

100.2 

31 

32 

100.5 

100.8 

101 1 

101.4 

101.7 

102.1 

102.4 

102.7 

103.0 

103.3 

32 

33 

103.6 

103.9 

104.3 

104.6 

104.9 

105.2 

105.5 

105.8 

106.1 

106.5 

33 

34 

106.8 

107.1 

107.4 

107.7 

108.0 

108.3 

108.6 

109.0 

109.3 

109.6 

34 

35 

109.9 

110.2 

110.5 

110.8 

111.2 

111.5 

111.8 

112.1 

112.4 

112.7 

35 

36 

113.0 

113.4 

113.7 

114.0 

114.3 

114.6 

114.9 

115.2 

115.6 

115.9 

36 

37 

116.2 

116.5 

116.8 

117.1 

117.4 

117.8 

118.1 

118.4 

118.7 

119.0 

37 

38 

119.3 

119.6 

120.0 

120.3 

120.6 

120.9 

121.2 

121.5 

121.8 

122.2 

38 

39 

122.5 

122.8 

123.1 

123.4 

123.7 

124.0 

124.4 

124.7 

125.0 

125.3 

39 

40 

125.6 

125.9 

126.2 

126.6 

126.9 

127.2 

127.5 

127.8 

128.1 

128.4 

40 

41 

128.8 

129.1 

129.4 

129.7 

130.0 

130.3 

130.6 

131.0 

131.3 

131.6 

41 

42 

131.9 

132.2 

132.5 

132.8 

133.2 

133.5 

133.8 

134.1 

134.4 

134.7 

42 

43 

135.0 

135.4 

135.7 

136.0 

136.3 

136.6 

136.9 

137.2 

137.6 

137.9 

43 

44 

138.2 

138.5 

138.8 

139.1 

139.4 

139.8 

140.1 

140.4 

140.7 

141.0 

44 

45 

. 

141.3 

141.6 

142.0 

142.3 

142.6 

142.9 

143.2 

143.5 

143.9 

144.2 

45 




































GAS AND OIL ENGINE HAND-BOOK 26 5 


Circumferences of Circles — Continued. 


| Diam . | 

.0 

.1 

.2 

.3 

A 

.5 

.6 

.7 

.8 

.9 

1 

s 

46 

144.5 

144.8 

145.1 

145.4 

145.7 

146.0 

146.3 

146.7 

147.0 

147.3 

46 

47 

147.6 

147.9 

148.3 

148.6 

148.9 

149.2 

149.5 

149.8 

150.1 

150.4 

47 

48 

150.7 

151.1 

151.4 

151.7 

152.0 

152.3 

152.6 

152.9 

153.3 

153.6 

48 

49 

153.9 

154.2 

154.5 

154.8 

155.1 

155.5 

155.8 

156.1 

156.4 

156.7 

49 

50 

157.0 

157.3 

157.7 

158.0 

158.3 

158.6 

158.9 

159.2 

159.5 

159.9 

50 

51 

160.2 

160.5 

160.8 

161.1 

161.4 

161.7 

162.1 

162.4 

162.7 

163.0 

51 

52 

163.3 

163.6 

163.9 

164.3 

164.6 

164.9 

165.2 

165.5 

165.8 

166.1 

52 

53 

166.5 

166.8 

167.1 

167.4 

167.7 

168.0 

168.3 

168.7 

169.0 

169.3 

53 

54 

169.6 

169.9 

170.2 

170.5 

170.9 

171.2 

171.5 

171.8 

172.1 

172.4 

54 

55 

172.7 

173.1 

173.4 

173.7 

174.0 

174.3 

174.6 

174.9 

175.3 

175.6 

55 

56 

175.9 

176.2 

176.5 

176.8 

177.1 

177.5 

177.8 

178.1 

178.4 

178.7 

56 

57 

179.0 

179.3 

179.9 

180.0 

180.3 

180.6 

180.9 

181.2 

181.5 

181.9 

57 

58 

182.2 

182.5 

182.8 

183.1 

183.4 

183.7 

184.0 

184.4 

184.7 

185.0 

58 

59 

185.3 

185.6 

185.9 

186.2 

186.6 

186.9 

187.2 

187.5 

187.8 

188.1 

59 

60 

188.4 

188.8 

189.1 

189.4 

189.7 

190.0 

190.3 

190.6 

191.0 

191.3 

60 

61 

191.6 

191.9 

192.2 

192.5 

192.8 

193.2 

193.5 

193.8 

194.1 

194.4 

61 

62 

194.7 

195.0 

195.4 

195.7 

196.0 

196.3 

196.6 

196.9 

197.2 

197.6 

62 

63 

197.9 

198.2 

198.5 

198.8 

199.1 

199.4 

199.8 

200.1 

200.4 

200.7 

63 

64 

201.0 

201.3 

201.6 

202.0 

202.3 

202.6 

202.9 

203.2 

203.5 

203.8 

64 

65 

204.2 

204.5 

204.8 

205.1 

205.4 

205.7 

206.0 

206.4 

206.7 

207.0 

65 

66 

207.3 

207.6 

207.9 

208.2 

208.6 

208.9 

209.2 

209.5 

209.8 

210.1 

66 

67 

210.4 

210.8 

211.1 

211.4 

211.7 

212.0 

212.3 

212.6 

213.0 

213.3 

67 

68 

213.6 

213.9 

214.2 

214.5 

214.8 

215.1 

215.5 

215.8 

216.1 

216.4 

68 

69 

216.7 

217.0 

217.3 

217.7 

218.0 

218.3 

218.6 

218.9 

219.2 

219.5 

69 

70 

219.9 

220.2 

220.5 

220.8 

221.1 

221.4 

221.7 

222.1 

222.4 

222.7 

70 

71 

223.0 

223.3 

223.6 

223.9 

224.3 

224.6 

224.9 

225.2 

225.5 

225.8 

71 

72 

226.1 

226.5 

226.8 

227.1 

227.4 

227.7 

228.0 

228.3 

228.7 

229.0 

72 

73 

229.3 

229.6 

229.9 

230.2 

230.5 

230.9 

231.2 

231.5 

231.8 

232.1 

73 

74 

232.4 

232.7 

233.1 

233.4 

233.7 

234.0 

234.3 

234.6 

234.9 

235.3 

74 

75 

235.6 

235.9 

236.2 

236.5 

236.8 

237.1 

237.5 

237.8 

238.1 

238.4 

75 

76 

238.7 

239.0 

239.3 

239.7 

240.0 

240.3 

240.6 

240.9 

241.2 

242.5 

76 

77 

241.9 242.2 

242.5 

242.8 

243.1 

243.4 

243.7 

244.1 

244.4 

244.7 

77 

78 

245.0 245.3 

245.6 

245.9 

246.3 

246.6 

246.9 

247.2 

247.5 

247.8 

78 

79 

248.1 248.5 

248.8 

249.1 

249.4 

249.7 

250.0 

250.3 

25 C .6 

251.0 

79 

80 

251.3 251.6 

251.9 

252.2 

i 

252.5 

252.8 

253.2 

253.5 

253.8 

254.1 

80 


Mensuration of Surface and Volume. The 

area of a rectangle is equal to the length X 
breadth. 

Area of a triangle is equal to the base X one- 
naif the perpendicular height. 

Diameter of a circle is equal to the radius X 2. 



























266 GAS AND OIL ENGINE HAND-BOOK 


Circumference of a circle is equal to the diam¬ 
eter X 3.1416. 

Area of a circle is equal to the square of 
diameter X .7854. 

Area of a sector of a circle is equal to the area 
of the circle X number of degrees in arc + 360. 

Area of surface of a cylinder is equal to the 
circumference X length, plus the area of both 
ends. 

To find the diameter of a circle having a given 
area: Divide the area by .7854, and extract the 
square root. 

To find the volume of a cylinder: Multiply 
the area of the section in square inches by the 
length in inches, this equals the volume in cubic 
inches. Cubic inches divided by 1728 is equal to 
the volume in cubic feet of any body. 

The surface of a sphere is equal to the square 
of diameter X 3.1416. 

Volume of a sphere is equal to the cube of 
diameter X .5236. 

The side of an inscribed cube is equal to the 
radius of the sphere X 1.1547. 

The area of the base of a pyramid or cone, 
whether round, square or triangular, multiplied 
by one-third of its height is equal to the volume. 

A gallon of water (United States Standard) 
weighs 8^ pounds and contains 231 cubic inches. 


INDEX 


Page 


Actual horsepower . 7 

Adjustment . 7 

—Carburetor . 23 

Anti-freezing solutions. 8 

Backfiring . 9 

Batteries, Dry . 82 

—Testing . 138 

Bearings . 9 

—Heated . 12 

—Thrust . 254 

Boat engine, Selecting a... 248 
Calorific values of fuels... 12 

Cams . 13 

Cam shaft gearing. 14 

Carburetor adjustment .... 23 

—Nozzle . 24 

Carburetors, Float-feed ... 16 

Care of gas or oil engines, 

Directions for . 26 

Cleaning a gas or oil engine 27 

Coil, Primary-spark . 193 

—Secondary . 204 

Combustion Chamber, Design 

of . 28 

—Dimensions of ...... 28 

Comparisons of gas and 

steam engines . 30 


Comparison of horizontal 


and vertical engines. 31 
Comparison of two and four¬ 
cycle gas engines.... 32 
Compressed air starters.... 33 

Compression . 35 

—Advantages of . 36 

—How to calculate.... 36 
—How to test for leaks 

in . 38 

—Loss of . 39 

Connecting-rods . 44 

Cooling of cylinder. 40 

Cooling systems . 40 

Couplings and thrust bear¬ 
ings . 254 

Crank shafts . 44 

Crude oil vaporizer. 182 

Cycles of gas and oil en¬ 
gines . 45 

Cylinder, Cooling the. 40 

—Method of boring a... 48 

—sweating . 49 

Cylinders, Construction of. 47 
Deep yvell pump plants.... 60 
De La Vergne crude oil en¬ 
gine . 50 


Page 


Design, Gas engine.255 

Design of gas and oil en¬ 
gines . 62 

Diesel engine . 63 

Dry batteries . 82 

Dynamometer . 83 

Efficiency, Thermal . 84 

—Mechanical . 83 

Electricity, Forms of. 85 

Electric light outfits. 85 

Engine efficiency . 117 

Engines, Gas and steam, 

compared . 30 

—Horizontal and verti¬ 
cal comparisons. 31 

—Two and four-cycle 
gas, comparisons of.. 32 

Exhaust valve, leaky. 91 

Explosions in the inlet-pipe 91 

—Weak . 92 

Fire insurance . 92 

Fire pot or muffler. 92 

Flash test of oils. 94 

Float-feed carburetors .... 16 

Flywheels . 95 

—Loose . 238 

Foundation bolts. 96 

Foundations . 97 

Four-cycle engine, Construc¬ 
tion of . 97 

—Operation of . 98 

—Principle of . 100 

Four-cycle marine engines. 102 

Friction clutches . 102 

Fuel consumption of gas 

and oil engines. 104 

Fuel gas oil. 105 

Fuels, Calorific heat values 

of . 12 

Gas and oil engines, Fuel 

consumption of .104 

Gas bag . 105 

Gas engine design.255 

Gas engine troubles.232 

Gases, Expansion of. 106 

Gasoline or kerosene fires.. 107 
Gasoline, How obtained... 106 

—pipes .. 242 

—traction engines .... 119 
Gas or oil engines, Success¬ 
ful operation of. 120 

Gas, Producer . 108 

Gearing, Cam shaft. 14 

267 








































































268 


INDEX 


Page 


Generator .. 121 

Governing gas or oil engines 121 

Hand starting device. 125 

Hornsby-Akroyd oil engine. 126 

Horsepower, Actual . 7 

—of gas or oil enrines. IPS 

Hot tube ignition. 131 

Hydrogen content . 118 

Ignition by compression.... 149 

—Catalytic . 132 

—Causes of premature. 193 

—dynamo . 139 

—Forms of . 132 

—Hot tube . 131 

—Jump-spark system of 135 
—Make-and-break sys¬ 
tem of . 135 

—mechanism . 134 

—Reason for advancing 

point of . 151 

Igniter, Cleaning an. 132 

Indicator diagrams . 151 

—Use of the. 154 

Inspecting gas or oil en¬ 
gines . 155 

Installing a gas or oil en¬ 
gine . 155 

Jump-spark wiring diagram 157 
Knocking or pounding in an 

engine . 157 

Lauson heavyTduty kerosene 

engine . 161 

Loose flywheel . 238 

Lubricants . 167 

Lubrication, Over or im¬ 
proper . 169 

—of oil engine cylinders 168 

Lubricators . 170 

Magnetos . 143 

Magneto Armature . 143 

Marine engine with reverse 

lever, Handling . 251 

Mensuration of surface and 

volume . 265 

Misfiring, Causes of. 171 

Mixing valve . 172 

Motor boats, Propellers for 251 

Muffler . 92 

Multiple-cylinder engines... 246 
Nordberg high compression 

oil engine . 173 

Nozzle, Carburetor . 24 

Oil engine cycle. 180 

—Hornsby-Akroyd .... 126 

—Remington. 213 

—Portable . 191 

Oiling a gas engine. 233 

Oils, Flash test of. 94 

—Viscosity of . 227 

Oil vaporization, Methods of 181 

Oil vaporizer, Crude. 182 

Oil vaporizers . 183 


Page 


Overheating, Causes of.184 

Piston displacement. 186 

—velocity . 189 

Piston-rings . . 187 

Method of turning. 187 

Pistons . 185 

—Length of . 186 

Portable oil engines. 191 

Pounding in an engine. 157 

Premature ignition, Causes 

of . 193 

Pressure leaks . 239 

Primary-spark coil . 193 

Primary-spark plug . 194 

Producer capacity. 117 

—efficiency . 117 

Producer, Gas .13, 108 

Froducer, Induced down- 

draft . 115 

—regulation . 118 

—The steam pressure.. 114 

Prony brake . 195 

Propellers for motor boats. 251 

Pump, Gasoline . 118 

Pump plants, Deep well.... 60 

Pumps . 240 

Regrinding valves. 242 

Remington oil engine. 197 

Repairing a gas or oil en¬ 
gine . 203 

Restricted exhaust or inlet 

ports . 243 

Secondary coil . 204 

Selecting a boat engine.... 248 
Smoke from cylinder, Cause 

of . 206 

Solders and spelters. 206 

Spark, Timing the. 237 

Spelters . 206 

Starting a gas engine. 206 

Starting a gasoline engine. 207 
Starting a gasoline or kero¬ 
sene engine for the 
first time . 208 


Starting a gas or oil engine, 

General directions for 208 
Starting a kerosene engine. 210 
Starting oil engines, New 

method of . 211 

Starting troubles. 212 

Stopping a gas or oil engine 213 

Stopping troubles . 214 

Tachometer . 214 

Tanks, Capacity of cylin¬ 
drical . 214 

—Installation of gaso¬ 
line . 214 

Testing batteries . 13S 

—the coil. 136 

Thermal efficiency . 84 

Throttle, Use of. 216 

Timing the spark. 237 





















































































INDEX 


269 


Page 


Two-cycle engine, Construc¬ 
tion of . 216 

—Principle of .218 

Two-cycle marine engine... 219 
Types of gasoline engines.. 245. 

Valve lifters . 224 

—Mixing . 172 

—operating mechanism. 224 

—stems. Fit of.225 

Valves . 220 

—and valve-chambers.. 221 


Page 

—Diameter and lift of. 222 

—regrinding .242 

—Timing of .225 

—Vaporizing .241 

Viscosity of oils.227 

Water cooling system.. 227 

Water-jacket circulation... 230 
—Draining the ....... 231 

—temperature ........ 239 

—Testing of.. 231 

Water-Jackets ...... 229 


TABLES 


Density and specific gravity 

equivalents . 257 

Dimensions of machine 

screws . 258 

Safe working load of steel 

balls . 258 

Composition of alloys.258 

Strength and weight of ma¬ 
terials . 259 

Dimensions of involute tooth 

spur gears . 259 

Melting point of metals.... 260 


Weight per cubic foot of 

substances . 260 

Squares and square roots of 
numbers from 1 to 100... 201 
Areas and circumferences < f 
circles from 0.05 to C.80, 
advancing by 1/20 of <. le 

inch . 262 

Circumferences of circles 
from 0.01 to 80.9 advanc¬ 
ing by lOtlis,.... 264 
























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